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First year > Microbiology semester 2 > Flashcards

Microbiology semester 2 Flashcards

1
Q

When the temperature is at its minimum what process happens to the bacterial cell membrane?

A

Gelling of the membrane.

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2
Q

What temperature does a psychrophile survive at?

A

4 degrees. (Can not survive more than 20).

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3
Q

What temperature does a mesophile survive at?

A

39 degrees.

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4
Q

What temperature does a thermophile survive at?

A

70 degrees.

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5
Q

What temperature does a extreme thermophile survive at?

A

106 degrees.

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6
Q

E.coli is a psychrophile. True or false?

A

False. It is a mesophile.

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7
Q

Psychrophile’s can survive at very low temperatures. This is partly because they have __________ membrane fludity.

A

Increased.

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8
Q

There is a higher content of what in the membrane of a psychrophile?

A

Unsaturated, polyunsatured and methyl branched fatty acids.

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9
Q

The membranes of psychrophiles have shorter acyl chain length. True or false?

A

True. This allows for increased membrane fluidity.

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10
Q

Psychrophiles produce antifreeze proteins. How do these help the bacteria survive at low temperatures?

A

They bind to small ice crystals inhibiting their growth by covering the water accessible surfaces of the ice.

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11
Q

Apart from antifreeze proteins, what other two substances do psychrophiles produce to help them survive in low temperatures?

A
  1. Cryoprotectants.

2. Cold adapted enzymes.

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12
Q

How do cold adapted enzymes differ from enzymes not adapted for cold temperatures?

A

There are more alpha helices and less interdomain interactions. This makes the enzyme more flexible.

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13
Q

Thermophiles use what to stabilize their DNA?

A

DNA binding proteins.

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14
Q

Themophiles have supercoils in their DNA. What produces these?

A

Reverse DNA gyrases.

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15
Q

What base pair is more commonly found in thermophiles?

A

GC.

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16
Q

The membrane of a thermophile is not linked by ester bonds. What type of bond does it use instead?

A

Ether bonds.

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17
Q

What interactions happen more commonly in the proteins of thermophiles?

A

Ionic and hydrophobic.

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18
Q

What is the concentration of H+ in the cell of a neurtophile?

A

10^-7.

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19
Q

What ion is pumped out of the respiratory chain, drives substrate symport, ATP synthesis and motility in alkaliphiles?

A

Na+.

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20
Q

What ion is pumped out of the respiratory chain, drives substrate symport, ATP synthesis and motility in acidophiles?

A

H+.

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21
Q

In response to osmotic stress water movement is regulated in bacteria. What is produced to help with this?

A

Compatible solutes.

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22
Q

What releases compatible solutes?

A

Mechano-sensitive channels.

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23
Q

What stabilizes the s-layer glycoprotein in some bacteria to help in varied osmotic pressure?

A

Na+.

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24
Q

What are the three toxic oxygen forms?

A
  1. Superoxide.
  2. Hydrogen peroxide.
  3. Hydroxyl radical.
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25
Q

How does superoxide form?

A

O2 + e- –> O2-

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26
Q

What enzymes detoxify hydrogen peroxide in water?

A

Catalase and peroxidase.

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27
Q

What enzymes detoxify superoxide in hydrogen peroxide and then in water?

A

Superoxide dismutase and catalase.

superoxide reductase and catalase.

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28
Q

What enzymes do obligate aerobes use to detoxify ROS?

A

Catalase and SOD.

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29
Q

What enzymes do facultative aerobes use to detoxify ROS?

A

Catalase and SOD.

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30
Q

What enzymes do aerotolerant anaerobes use?

A

SOD.

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31
Q

What is a Petroff-Hausser used for?

A

To count cells.

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32
Q

What does flow cytometry allow you to do?

A

Distinguish between live and dead cells.

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33
Q

Serial dilutions are used in what method of cell counting?

A

Viable counting.

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34
Q

Optical density is an example of how you can indirectly look at bacterial growth. What are three limitations of this method?

A
  1. High cell density needed.
  2. Can not distinguish between live and dead cells.
  3. The OD value given depends on the shape of the organism.
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35
Q

What type or organism can you not use a spectrometer on?

A

Moulds and fillamentous bacteria.

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36
Q

Are dry weight and looking a metabolic activity of a bacterial cell direct or indirect methods in determine the bacterial growth?

A

Indirect.

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37
Q

What are the four stages on the bacterial growth curve?

A

Lag, log, stationary, death.

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38
Q

What is the definition of the thermal death point?

A

The minimal temperature in which all organism are killed in 10 minutes in a particular liquid.

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39
Q

What is the thermal death time?

A

The minimum time needed to kill all organisms in a particular liquid at a given temperature.

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40
Q

What conditions are needed in the .moist heat’ method of bacterial control?

A

15 minutes at 121 degrees.

If the culture consists of spores you need to place the culture under pressure.

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41
Q

What conditions are needed for the ‘dry heat’ method of bacterial control?

A

Direct flaming or incineration over 150 degrees for 2 hours.

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42
Q

What conditions are needed for the pasteurization method of bacterial control?

A

Below 100 degrees.

HTST is at 72 for 15 seconds.
UHT is at 140 for 2 seconds.

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43
Q

Filtration can be used to sterilize gases and what type of liquids?

A

Liquids that are sensitive to the heat methods.

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44
Q

What does a bacteriostatic chemical to do bacterial growth?

A

It stops the growth.

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45
Q

What does a bactericidal chemical to do bacterial growth?

A

It stops growth AND kills the bacteria.

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46
Q

What does a bacteriolytic chemical to do bacterial growth?

A

It causes the cells to lyse. You can hence not measure this interaction with a spectrometer as it will not have an OD value.

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47
Q

What do sterilants do?

A

They completely eradicate all forms of bacteria including spores. Used on objects.

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48
Q

What is ethylene oxide gas an example of?

A

A sterilant.

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49
Q

What do disinfectants do?

A

They kill microorganisms but not necessarily spores. Used on objects.

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50
Q

What is 60-85% alcohol an example of?

A

A disinfectant.

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51
Q

What do antiseptics and germicides do?

A

Inhibit growth or kill microorganisms on living tissues.

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52
Q

Do you need a pure culture for the disk diffusion technique, testing antibiotic resistance?

A

Yes.

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53
Q

What is the definition of the ‘minimum inhibitory concentration’ (MIC)?

A

The lowest concentration of a drug inhibiting the visible growth of a test organism after overnight incubation.

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54
Q

What is the definition of the ‘ minimum bacterial concentration’ (MBC)?

A

Lowest concentration of drug killing 99.9% of a test organism after overnight incubation.

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55
Q

What are TCP, chlrohexidine and Triclosan examples off?

A

Phenolytic compounds.

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56
Q

What can phenolytic compounds be used as at low concentrations?

A

A local anesthetic.

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57
Q

What do phenolytic compounds do to the cell at high concentrations?

A

They disrupt the cytoplasmic membrane and denature proteins.

60-85% alcohols also do this to the cell.

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58
Q

What are QUATS?

A

Quaternary ammonium compounds, an example of cationic detergents.

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59
Q

What do QUATS do?

A

Interact with phospolipids of the cytoplasmic membrane.

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60
Q

What sort of chemical used for antimicrobial control is an alkylating agent?

A

Aldehydes.

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61
Q

Formatin solution and formaldehyde gas do what to a cell?

A

They modify proteins and DNA causing cell death.

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62
Q

What are the two types of halogen releasing agents?

A
  1. Chlorine releasing agents.

2. Iodine releasing agents.

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63
Q

What do chlorine releasing agents do to the cell?

A

They form chlorinated bases in DNA and oxidise proteins.

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64
Q

What type of halogen reducing agent causes stains?

A

Iodine reducing agents.

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65
Q

When was the Black Plague?

A

1328-1350.

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66
Q

What percentage of Europe’s population was killed by the black plague?

A

30-50%

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67
Q

When was the Flu pandemic?

A

1918.

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68
Q

What percentage of the worlds population was killed in the 1918 flu pandemic?

A

3-5%.

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69
Q

What did Rudolph Emmerich & Oscar Loew discover?

A

That Pyocynase had antibacterial properties. However their effectiveness was sporadic and it is toxic.

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70
Q

What did Gerhard Domagk discover?

A

Protosil red.

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71
Q

There are 10 main classes of antibiotics all inhibiting processes in the cell. What are these processes ?

A
  1. Cell wall synthesis.
  2. Fatty acid metabolism.
  3. Cytoplasmic membrane structure and function.
  4. Lipid biosynthesis.
  5. Protein synthesis (tRNA).
  6. Protein synthesis (30s inhibitors).
  7. Protein synthesis (50s inhibitors).
  8. DNA directed RNA polymerase.
  9. RNA elongation.
  10. DNA gyrases.
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72
Q

According to WHO, how many people die of health care associated infections each year in Europe?

A

4.5 million.

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73
Q

According to WHO, how many people die of health care associated infections each year in the USA?

A

1.7 million.

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74
Q

It costs the US an estimated £4 billion a year to treat health care associated infections. How much do they cost Europe a year in direct costs?

A

£6 billion.

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75
Q

B-lactams and Glycopeptides belong to which class of antibodies?

A

Cell wall inhibitors.

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76
Q

Aminoglycosides, cyclines, MLS and oxazolidinones all belong to which class of antibodies?

A

Protein synthesis inhibitors.

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77
Q

Quinolones belong to which class of antibodies?

A

DNA metabolism inhibitors.

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78
Q

What must a good antibiotic do?

A

Must inhibit and essential process.

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79
Q

What is the definition of pharmacokinetics?

A

The branch of pharmacology concerned with the movement of drugs within the body.

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80
Q

What is the definition of pharmacodynamics?

A

The branch of pharmacology concerned with the effects of drugs and the metabolism of their action.

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81
Q

What does B lactam inhibit?

A

Peptidoglycan polymerisation.

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82
Q

What mediates peptidoglycan polymerisation?

A

D.D- transpeptidases. These are also known as penicillin binding proteins.

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83
Q

B lactams bind to penicillin binding proteins, inactivating the enzymes irreversibly. This happens because penicillin is a structural analogous of what?

A

D-ala-D-ala-C residues in the peptide stem.

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84
Q

Resistance has caused a ______ in the Penicillin Binding Proteins affinity for beta lactams.

A

Reduction.

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85
Q

Can gram positive or gram negative bacteria secrete antibodies?

A

Gram negative.

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86
Q

Because of resistance developing there has been modifications in the ________ targeted by B lactams.

A

Synthetic pathway.

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87
Q

What enzyme can inactive B lactams?

A

B lactamases.

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88
Q

How do B lactamases work?

A
  1. Nucleophilic attack by catalytic serine.
  2. Covalent complex formed from penicillin and B lactamases.
  3. Hydrolysis of penicillin.
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89
Q

What do autotrophs fix into organic molecules?

A

CO2.

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90
Q

What organic molecules are generally produced from auxotrophs?

A

Sugars, especially sucrose.

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91
Q

What type of organism obtains energy from chemical reactions?

A

Phototrophs.

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92
Q

What organisms maintain energy from oxidation and reduction reactions?

A

Chemotrophs.

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93
Q

What type of organism uses organic molecules as a source of electrons?

A

Lithotrophs.

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94
Q

What is the definition of phototrophy?

A

The harness of photo excited electrons to power cell growth.

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95
Q

How many light driven pumps does Bacteriarhodopsin have?

A

1.

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96
Q

What sort of organisms contain proteorhodopsin?

A

Marine proteobacteria.

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97
Q

What sort of bacteria contain Bacteriarhodopsin?

A

Halophillic bacteria.

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98
Q

______ alpha helices span the BR membrane in alternating directions. These surround a molecule of _______ which is linked to a ________ residue.

A
  1. 7
  2. Retinal
  3. Lysine.
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99
Q

When a photon is absorbed by retinal it’s conformation changes. How?

A

Cis to trans.

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100
Q

What type of synthase does BR have?

A

F1F0.

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101
Q

BR only provides a mechanism for what?

A

ATP synthase. Another method for metabolism is also needed.

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102
Q

What bacterium contains ER?

A

Halobacterium salinarium.

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103
Q

BR forms trimers which pack into ________ arrays.

A

Hexagonal.

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104
Q

What colour membrane does Haliobacterium salinarium have?

A

Purple.

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105
Q

What metabolic process does Haliobacterium salinarium use?

A

Photoheterotrophy.

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106
Q

What happens to water because of photoexcitation?

A

Photolysis.

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107
Q

What photosystem is water split at?

A

2.

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108
Q

What type of chlorophyll splits the water?

A

P680.

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109
Q

Cyanobacteria have a different set of ________.

A

Accessory pigments.

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110
Q

What type of chlorophyll is in PS1?

A

P700z

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111
Q

Can both photosystems absorb light?

A

Yes.

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112
Q

What is shape does the pathway of hydrogen ions make?

A

Z.

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113
Q

What reduction potential does photosystem 2 have?

A

+820mv.

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114
Q

How many photosystems are used in anoxygenic photosynthesis?

A

1.

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115
Q

What type of system uses bacteriochlorophyll?

A

Anoxygenic photosynthesis.

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116
Q

What end of the spectrum does bacteriochlorophyll absorb?

A

Red.

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117
Q

Can bacteriochlorophyll allow photolysis?

A

No. There is not enough energy at the red end of the visible light spectrum to split water.

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118
Q

Why can organisms with bacteriochlorophyll exploit deep bodies of water?

A

Because red lights wavelength is long enough to penetrate down.

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119
Q

What photosystem does green sulphur bacteria use?

A

1.

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120
Q

What are chlorobia?

A

Green sulphur bacteria.

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121
Q

What type of light do green sulphur bacteria use?

A

Far red.

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122
Q

Where are electrons transferred to in anoxygenic photosynthesis which just uses photosystem 1?

A

NAD+.

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123
Q

What is the redox potential at PS1?

A

-400mv. It is not far down enough to split water but it can split H2S.

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124
Q

Is cyclic phosphorylation in lived in anoxygenic photosynthesis at photosystem 1 or 2?

A

2.

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125
Q

What type of bacteria use photosystem 2 in anoxygenic photosynthesis?

A

Alphaproteobacteria.

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126
Q

What are alphaproteobacteria also known as?

A

Purple non sulphur bacteria.

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127
Q

What light to purple non sulphur bacteria use?

A

Infra red.

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128
Q

Where do purple non sulphur bacteria separate the electrons from?

A

Bacteriochlorophyll.

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129
Q

Where do green sulphur bacteria get their electrons from?

A

H2S or an organic electron donor such as succinate or reduced iron.

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130
Q

Cyclic phosphorylation can make ATP and NADPH. True or False?

A

False. It can not make NADHP or NADH. To do this it has to use reverse electron transport.

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131
Q

What is the definition of lithotrophy?

A

Acquisition of energy by oxidation of inorganic electron donors.

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132
Q

What can reduced inorganic electron donors be oxidised by?

A

Fe2+, NH4+, H2S.

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133
Q

What does the terminal electron acceptors have to be when reduced inorganic compounds are acting as electron donors in lithotrophy?

A

A strong oxidant, such as oxygen and NO3-.

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134
Q

Why is a strong oxidant required as an electron acceptor in lithotrophy?

A

Most inorganic substrates are relatively poor electron donors.

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135
Q

What is the following process also known as?

Ammonium- Hydroxylalamine- Nitrous acid (Nitrite)- Nitric acid (Nitrate)

A

Nitrogen oxidation.

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136
Q

What is the following process also known as?

Hydrogen sulphide- Elemental sulphur- Thiosulphate- Sulphuric acid

A

Sulphur and metal oxidation.

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137
Q

What can microbial sulphur oxidation cause?

A

Severe environmental acidification and eroding of structures.

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138
Q

Microbes that carry out sulpur/ metal oxidation are adapted to a low pH. True or false?

A

False. Although they are adapted to the low pH of sulphuric acid they are not adapted to the low pH caused by any other acid.

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139
Q

What organism can oxidise ferrous sulphide?

A

Ferroplasma.

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140
Q

Lithotrophy is similar to anerobic respiration. True or false?

A

True.

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141
Q

What is the process called that uses hydrogen as an electron donor?

A

Hydrogentrophy.

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142
Q

What is used as the electron donor in dehalorespiration?

A

Hydrogen.

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143
Q

What is dehalorespiration an example of?

A

A a process which allows bioremediation.

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144
Q

Tetrachloroethane is a common environmental pollutant used in what?

A

Dry cleaning.

It is still used to removed deposits from engines.

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145
Q

Where does tetrachloroethane end up in the environment?

A

Aquifers and water sources. This includes the South Downs in the UK. The same issue happens in the US and India.

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146
Q

What can tetrachloroethane be reduced to?

A

Ethane.

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147
Q

The reduction of tetrachloroethane into ethane can have negative effects if tetrachloroethane is only partially reduced- forming what?

A

Vinyl chloride, a toxic compound.

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148
Q

Will one organism do each step in the reduction/ oxidation process?

A

No- it will normally do the step that gives it the most energy. This is normally one or two steps.

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149
Q

As each successive TCA is used up it’s reduced form appears; the next best electron acceptor is used generally by what?

A

By a different microbe species.

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150
Q

Where are the quinol electrons transferred to in aerobic respiration?

A

A terminal oxidoreductase eg Cyt.

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151
Q

What drives the proton motor force?

A

A change in pH. Not a single proton.

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152
Q

Besides ATP synthesis what three things does the proton motor force drive?

A

Rotation of flagella, uptake of nutrients and efflux of toxic drugs.

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153
Q

What is the definition of biosynthesis/ anabolism?

A

The building of complex biomolecules. This requires the central elements and metal ions.

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154
Q

What three things can produce energy for anabolism?

A
  1. coupling of ATP hydrolysis.
  2. NADPH oxidation.
  3. Ion flown down a transmembrane concentration gradient.
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155
Q

Is NADPH a reducing or oxidising agent?

A

Reducing agent.

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156
Q

What 4 categories of organisms perform CO2 fixation?

A
  1. Oxygenic phototrophic.
  2. Chloroplasts.
  3. Facultative anaerobic purple bacteria.
  4. Lithotrophic bacteria.
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157
Q

What is methanogenesis?

A

Reduction of carbon dioxide and other single carbon compounds to methane.

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158
Q

What class of organisms are methanogens?

A

Archaea.

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159
Q

What process do methanogens do?

A

Methanogenesis.

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160
Q

What is the simplest form methanogenesis?

A

Hydrogen reduction in carbon dioxide.

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161
Q

Why is methane as problem in landfill sites?

A

It is very flammable.

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162
Q

What organisms can utilise methane?

A

Methanotrophs.

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163
Q

What is this an example off?

CO2 + 4H2 –> CH4 + 2H20

A

Methanogenesis.

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164
Q

How many ATPs are used in the reverse TCA cycle?

A

4-5.

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165
Q

Is the reverse TCA cycle described as oxidative or reductive?

A

Reductive.

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166
Q

What is Biosynthasis/anabolism?

A

The building of complex molecules. This requires the essential elements and some metal ions.

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167
Q

Where can the energy for anabolism come from?

A
  1. Coupling of ATP hydrolysis.
  2. NADPH oxidation.
  3. Ion flow down a transmembrane concentration gradient.
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168
Q

What molecule is fixated in the reductive pentose phosphate cycle?

A

CO2.

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169
Q

What categories of organisms perfrom the reductive pentose phosphate cycle?

A
  1. Oxygenic phototrophic bacteria.
  2. Chloroplasts of algae and plants.
  3. Facultative anaerobic purple bacteria.
  4. Lithotrophic bacteria.
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170
Q

What are methanogenesis and lithotrophy both similar too?

A

Anaerobic respiration.

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171
Q

What is anaerobic respiration?

A

The use of a compound that isn’t oxygen as the final electron acceptor.

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172
Q

What organisms use NO3-, NO2- and fumerate as the final electron acceptor?

A

Archae and bacteria.

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173
Q

What type of respiration do E.coli use?

A

Facultative.

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174
Q

What are the two best final electron acceptors to use in anaerobic respiration?

A

Hydrogen and NADH.

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175
Q

Hydrogen and NADH are the best final electron acceptors to use in anaerobic respiration. What other three electron acceptors can be used?

A

Formate, lactate and succinate.

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176
Q

Does rubisco have a low or high affinity to CO2?

A

Low.

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177
Q

What is photorespiration?

A

The process in which oxygen competes with carbon dioxide by binding to rubisco. This leads to the production of 2-phosphoglycolate instead of 3-phospoglycolate.

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178
Q

If you could improve the affinity of carbon dioxide to rubisco what else could you improve?

A

Crop yield. Unfortunately the affinity cant be improved as it would involve changing the structure of the enzyme which is essential for its structure.

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179
Q

What does CCM stand for?

A

Carbon concentrating mechanism.

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180
Q

What does the CCM covert carbon dioxide to through the use of carbonic anhydrase and why?

A

HCO3-. It does this as HCO3- can be retained in the cell, unlike CO2 which can diffuse out of the cell membranes.

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181
Q

What special structure is Rubsico found in in many organisms?

A

A carboxysome. Carbonic anhydrase acts within this structure.

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182
Q

What happens in the carboxysome?

A

Carbonic anhydrase converts HCO3- back to CO2.

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183
Q

Are all the reactions in the TCA cycle reversible?

A

No, but most of them are.

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184
Q

What can happen as a result of the TCA cycle being reversible?

A

A small amount of CO2 can be produced and fixated to regenerate TCA cycle intermediates.

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185
Q

What organisms can reverse the whole TCA cycle?

A

Some archae and some bacteria.

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186
Q

What three enzymes can be reversed in the TCA cycle?

A
  1. ATP citrate lysase.
  2. Fumerate reductase.
  3. Oxoglutarate: FD oxidoreductase.
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187
Q

What performs reduction in the reverse TCA cycle?

A

NADPH or NADH.

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188
Q

What is reduced in the reverse TCA cycle?

A

Ferredoxin.

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189
Q

The reverse TCA cycle may predate the TCA cycle. True or False?

A

True.

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190
Q

Nitrogen fixation only happens in bacteria and archae. True or false?

A

False. It may happen at a low level in fungi.

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191
Q

What have aquatic cyanobacteria developed to allow them to fixate nitrogen?

A

Heterocysts (filaments).

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192
Q

What can attach to bacteria to further reduce oxygen levels?

A

Sugars.

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193
Q

What is turned of to allow nitrogen fixation to occur?

A

Photosynthesis. This allows anaerobic conditions to be maintained.

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194
Q

What enzyme catalyses nitrogen fixation?

A

Nitrogenase.

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195
Q

How many ATPs are consumed per N2 fixed in nitrogen fixation?

A

Around 28.

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196
Q

The harber bosch process fixates nitrogen to produce what?

A

Nitrogen fertiliser.

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197
Q

How many reduction cycles through nitrogenase occur in nitrogen fixation?

A

4.

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198
Q

What is the first reduction cycle to occur through nitrogenase in nitrogen fixation?

A

Fe protein gains 2 electrons from an electron transport protein (eg ferredoxin.) The electrons are then transferred to a FeMo centre.

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199
Q

What is the second reduction cycle to occur through nitrogenase in nitrogen fixation?

A

The FeMo centre binds 2H+ which is then reduced into H2 gas.

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200
Q

What is the third reduction cycle to occur through nitrogenase in nitrogen fixation?

A

N2 binds to the active site displacing the H2 gas.

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201
Q

What is the fourth reduction cycle to occur through nitrogenase in nitrogen fixation?

A

Successive pairs of H+ and e- reduce nitrogen to ammonium.

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202
Q

Do the number of complexes in nitrogenase vary between organisms?

A

Yes. However the complex is only thought to have evolved once.

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203
Q

What is the definition of the immune system?

A

An integrated system of cells and molecules that defend against disease by reacting against a parasite.

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204
Q

Herceptin is an antibody used in the treatment of what?

A

Cancer.

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205
Q

Invertebrates and vertebrates both use negative surveillance in their immune response. What does this mean?

A

All cells are labelled with proteins. Any unlabelled cells will be destroyed by phagocytes.

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206
Q

What is the downside of using negative surveillance in the immune response?

A

It is relatively easy for pathogens to learn how to mimic.

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207
Q

What protein is used in the vertebrate negative surveillance system to overcome the problem of mimicry?

A

Major histocompatibility proteins. These are very polymorphic which makes them hard to mimic.

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208
Q

What can positive surveillance do that negative surveillance can not do?

A

It can specifically identify foreign cells and destroy them.

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209
Q

What are the major two branches of the immune system?

A

Innate and Adaptive.

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210
Q

Which of the following statements is false?

  1. You are born with the innate immune system.
  2. There is an enhanced second response.
  3. It can responded within minutes/hours.
A

Statement two. There is no enhanced second response with the innate immune system.

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211
Q

Which of these following statements is false?

  1. You are born with no adaptive immune system, instead it develops throughout your life.
  2. It is a highly specific response which improves after the first encounter.
  3. It is a slower response than the innate immune system. It takes days/weeks instead of months and hours.
A

Statement one is false. You are born with some adaptive immunity although most does develop throughout your life.

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212
Q

Phagocytes, NK cells, and B/T lymphocytes are all examples of what?

A

Leucocytes / White blood cells.

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213
Q

Phagocytes, NK cells and B/T lymphoyctes are all examples of white blood cells. Which one of the above is part of the adaptive immune response?

A

B/T lymphocytes.

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214
Q

Lysosome, complement, interferons and antibodies are all exmaples of what?

A

Soluble factors.

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215
Q

Lysosomes, complement, interferon’s and antibodies are all soluble factors. Which one is also part of the adaptive immune response?

A

Antibodies.

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216
Q

What is something ‘non self’ usually described as?

A

An antigen.

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217
Q

After initial contact with an antigen the innate response is triggered. Is the adaptive response also triggered?

A

Yes, but it is weak.

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218
Q

When there is a secondary contact with an antigen is the innate response still triggered?

A

No. The adaptive response is triggered.

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219
Q

Are external barriers classified as innate or adaptive methods of response?

A

Innate.

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220
Q

Tears and sweat contain lysosomes. What do these do to the bacteria?

A

Break down their cell wall.

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221
Q

The pH of the stomach allows a large amount of microorganisms to be killed. What is this pH?

A

2.5.

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222
Q

What are commensals?

A

Friendly bacteria which produce chemicals to influence the immune system.

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223
Q

Where do leucocytes originate from?

A

The bone marrow.

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224
Q

What did Elie Metchnikoff discover in 1883?

A

Phagocytes.

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225
Q

What is the comment phagocyte in the blood?

A

Neutrophils.

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226
Q

What do neutrophils contain?

A

A strange shape nucleus and granules compromised of specialised lysosomes.

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227
Q

When will neutrophils not be short lived?

A

If they find an infection.

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228
Q

What do lysosomes in the granules of neutrophils release?

A

Enzymes and H2O2.

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229
Q

What colour tinge do the granules in neutrophils have?

A

Green.

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230
Q

Mononuclear phagocytes can be found in and outside of the blood. When in the blood they are called monocytes. What are they called when they are found in tissues?

A

Macrophages.

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231
Q

How long can monocytes/macrophages live for?

A

Months and years.

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232
Q

Do mononuclear phagocytes (monocytes/macrophages) or neutrophils help initiate an adaptive response?

A

Mononuclear phagocytes as these are more complex.

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233
Q

What two types of infections are phagocytes good at fighting?

A

Bacterial and fungal.

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234
Q

Are neutrophils, monocytes and macrophages all examples of phagocytes?

A

Yes. They are also all leucocytes and are part of the innate immune response.

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235
Q

Natural killer cells are a type of leucocyte. What do they do?

A

Kill virally infected host cells non specifically.

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236
Q

What may Natural Killer cells be able to kill?

A

Cancer cells.

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237
Q

What are PRR’s?

A

Pathogen recognition receptor. These are found on the surface of phagocytes. Eg Toll- Like receptor 4 recognises lipopolysaccharides.

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238
Q

When will a natural killer cell kill a cell?

A

When it does not recognise a self protein (eg. MHCI).

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239
Q

How quickly are soluble factors produced in response to an infection?

A

Very quickly.

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240
Q

What is the compliment system mad up of?

A

Approximately 20 proteins in the blood which are only activated when there is an infection. They can cause cell lysis and phagocytosis.

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241
Q

What are defensins?

A

Small positively charged proteins that can disrupt bacterial membranes. They are produced by neutrophils. Defensins are an example of a soluble factor

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242
Q

What are interferons?

A

Interferons are produced by virally infected cells. They protect unaffected cells and activate macrophages and natural killer cells. They can interfere with viral replication.

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243
Q

What causes swelling?

A

The shrinkage of cells lining the capillaries allowing tissue to leave the blood and enter the tissues. Phagocytes then migrate into tissues.

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244
Q

What is inflammation induced by?

A

The production of cytokines. These cytokines are produced by macrophages already resident in the tissue. The cytokines send signals to other cells resulting in a larger response.

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245
Q

What can histamine cause?

A

Inflammation.

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246
Q

What type of response is a temperature rise after infection?

A

An acute phase response.

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247
Q

To stimulate an acute phage response what do macrophages produce apart from produce cytokines?

A

Interleukin 1 (IL-1).

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248
Q

What three things does Interleulkin 1 (produced by macrophages) do?

A
  1. Raises temperature.
  2. Stimulates phagocytosis.
  3. Reduces the level of iron in the blood.
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249
Q

Although Interleukin 1 is produced locally, where does it act upon in the body?

A

The hypothalamus in the brain.

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250
Q

One of the things Interleukin 1 does as part of the acute phase response is to reduce the levels of iron within the blood. Why is this helpful?

A

As bacteria are very reliant on iron for growth.

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251
Q

The adaptive immune system can cause a ______ response.

A

Specific.

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252
Q

What are the receptors for B lymphocytes?

A

Antibodies.

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253
Q

What are the receptors for T lymphocytes?

A

T cell receptors.

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254
Q

What type of organism causes sleeping sickness?

A

Parasites.

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255
Q

What happens inside the peripheral lymphoid tissue?

A

Antigen dependant differentiation.

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256
Q

Is the response from B cells known as humoral or cell mediated?

A

Humoral.

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257
Q

Is the response from T cells known as humoral or cell mediated?

A

Cell mediated.

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258
Q

How do B cells respond to antigens?

A

They secrete antibodies with bind to foreign material targeting it for destruction.

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259
Q

How do T cells respond to antigens?

A

They can kill the infected cells directly or make proteins called cytokines which instruct other cells to behave.

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260
Q

T cells can produce cytokines when coming across an antibody which instruct other cells on how to behave. What are these other cells?

A

B cells, natural killer cells and macrophages.

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261
Q

Can natural killer cells or T cells kill infected cells more directly?

A

T cells.

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262
Q

Extracellular bacterial and 2andry viral antigens are all targeted by what type of lymphocyte?

A

B.

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263
Q

Viral, intracellular bacterial and intracellular parasitic antigens are all targeted by what type of lymphocyte?

A

T.

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264
Q

What happens to lymphocytes that recognise ‘self’ cells?

A

They are deleted early in development.

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265
Q

What does the clonal selection hypothesis say happens when a B lymphocyte recognises the correct antigen?

A

It divides and differentiates.

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266
Q

What are the two things that can compromise a vaccine ?

A
  1. Subunits (eq toxoids)

2. Attenuated strains.

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267
Q

Can T cells only recognise an antigen when it is bound to a host cell?

A

Yes.

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268
Q

What happens in the primary lymphoid tissue in regards to lymphocytes?

A

The lymphocytes reach maturity.

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269
Q

What happens in the secondary lymphoid tissue in regards to lymphocytes?

A

The mature lymphocytes can be stimulated by antigens.

270
Q

What are the two types of T cells?

A

T helper and T cytotoxic cells.

271
Q

What are antibodies widely used in outside the human body?

A

Research and medicine.

272
Q

Antigens are detected by B lymphocytes. There are they turned into what to ultimately produce a soluble antibody?

A

Plasma cells.

273
Q

What type of molecule is an immunoglobulin?

A

A soluble glycoprotein.

274
Q

Where were immunoglobulins discovered?

A

Serum.

275
Q

What does the Fc region of antibody/ immunoglobulin allow?

A

Antigen elimination. The region is constant allowing it to act with elements of the innate immune system.

276
Q

What is the total size of an immunoglobulin?

A

150kd. Each light arm is 25kd and each heavy arm is 50kd.

277
Q

What does the Fab region on an immunoglobulin stand for?

A

Fragment antigen binding.

278
Q

What does the Fc region on an immunoglobulin stand for?

A

Fragment crystallisable.

279
Q

Who discovered that there were 4 polypeptide chains and 12 domains in an antibody?

A

Rodney Porter.

280
Q

What amino acid is present in the hinge region of an antibody?

A

Proline.

281
Q

When Rodney Porter treated the antibody with papain 2 fragments where produced. One of these was bound to the antibody and the other was crystallised in a solution. There was a 2:1 ratio. What enzyme was used to cleave the other side of the hinge?

A

Pepsin.

282
Q

Are the variable and constant regions of an antibody encode for by the same exon?

A

No.

283
Q

How do the imunoglobin classes differ?

A

In amino acid sequence in the heavy chain.

284
Q

What are the two types of light chain?

A

Kappa and Lambda.

285
Q

In one molecule will there only be one type of light chain?

A

Yes.

286
Q

What are the 5 classes of antibodies?

A

G,M,A,D,E (discovered in that order).

287
Q

What can happen in regards to exons to give antigens more specificity?

A

Multiple variable region exons can recombine and mutate during B cell differentiation.

288
Q

What is the main class of antibody found in tissue and serum?

A

G.

289
Q

What class of antibody can cross the placenta?

A

G.

290
Q

What is the IgG antibody important for?

A

Secondary/memory responses.

291
Q

What is the first type of antibody made in primary responses?

A

M.

292
Q

What class of antibody forms a pentamer (polymer)?

A

M.

293
Q

What type of antibody forms a dimer/ polymer in secretions?

A

A.

294
Q

What class of antibody is found in saliva, tears, breast milk and mucus?

A

A.

295
Q

What class of antibody has a long hinge?

A

D.

296
Q

What percentage of antibodies are D class?

A

1%.

297
Q

What class of antibody has extra domains?

A

E.

298
Q

What class of antibody is present at very low levels?

A

E.

299
Q

What class of antibody is involved in allergies?

A

E.

300
Q

IgM is the first antibody type to be made in primary responses. Is it made at higher levels in secondary responses?

A

No.

301
Q

What is the main way that antibodies can protect against infection?

A

Specific binding/ multivalency of FAB.

302
Q

What can IgG and IgA do to help protect against infection?

A

They can neutralise toxins.

303
Q

What antibody class can immobilise motile microbes due to the fact that it is a pentomer and can bind up to 10 antigens?

A

M.

304
Q

What are IgA and IgM both very good at forming?

A

Complexes.

305
Q

What class of antibody protects mucosal surfaces?

A

A.

306
Q

What type of antibodies form an active complement?

A

G and M, but especially M.

307
Q

Phagocytes have FC receptors for which classes of antibodies?

A

G and A.

308
Q

Mast cells have FC receptors for which class of antibodies?

A

E.

309
Q

Natural killer cells have Fc receptors for which class of antibodies?

A

G.

310
Q

Is compliment the immune defence against bacteria, fungi or viruses?

A

Bacteria. It is not known if it is the immune defence against viruses.

311
Q

What enzyme is first activated when compliment is stimulated?

A

Proenzyme 1.

312
Q

What does proenzyme 1 activate in the compliment cascade?

A

Enzyme 1. This activates proenzyme 2 which in turn activates enzyme 2 and so on.

313
Q

What pathway is activated specifically by antigen/antibody complexes?

A

Classical pathway.

314
Q

What pathway is activated by certain bacteria?

A

MB-Lectin or Alternative pathway.

315
Q

What does the 3rd component of the pathway have?

A

Protease activity. It is also the most abundant. Other components have protease activity too just not as much.

316
Q

What is the definition of complement?

A

A series of proteins in serum normally inactive but can be activated in different ways.

317
Q

What are the three main activities of complement?

A
  1. Activation
  2. Opsonisation
  3. Cell lysis.
318
Q

What does activation involve?

A

Phagocyte recruitment and the induction of inflammation.

319
Q

C5a and C3a are chemoattractants. What stage of complementation are they involved in?

A

Activation.

320
Q

What stage of complement is being described here?

Chemoattractants, such as C5a and C3a influence cell movement. Phagocytes have receptors for C5a and C3a so will move to areas which have a higher C5a/ C3a concentration. This is known as phagocyte recruitment. Anaphylatoxins are produced in an extreme allergic reaction. This causes widespread inflammation. Mast receptors will then release histamine.

A

Activation.

321
Q

What can anaphylatoxins also be known as?

A

Compliment proteins.

322
Q

What stage of complementation is being described here?

C3B binds to the bacterial cell surface making it more attractive to phagocytes. This is because phagocytes have receptors for C3b. This allows the phagocytes to bind better to the bacterial cell.

A

Opsonisation.

323
Q

What stage of complement is being described here?

The whole complement is involved in this step (C1 - C9). There is formation of a membrane attack complex. C9 polymerises this which forms a hollow cyndrical structure which can insert into the bacterial membrane causing pores and lysis. This process also allows the disruption of envelopes in some viruses.

A

Cell lysis.

324
Q

What does the classical pathway require?

A

Ab/Ab2. It also needs two antibodies bound next to each other on a bacterial cell surface.

325
Q

What is the structure of C1 in the classical pathway?

A

Tulip branch structure of 6 globular heads and a collagen stalk.

326
Q

How many Fc regions must C1 interact with?

A

2.

327
Q

When C1’s tulip branch structure interacts with the Fc region of two antibodies what happens to allow the C1 to act as a protease?

A

A steric change.

328
Q

When C1 acts as a protease what does this activate?

A

The rest of the compliment.

329
Q

Does the collage stalk in C1 have any flexibility when it comes to binding antigens?

A

Yes, some.

330
Q

Why it is easier for IgM to find two antigens?

A

It is a pentemer.

331
Q

Some classes of antibodies can act as opsonins. What is an opsonins?

A

An antibody or other substance which binds to foreign microorganisms or cells making them more susceptible to phagocytosis.

332
Q

What classes of antibodies can act as opsonins?

A

G and A.

333
Q

What do sudapods encapsulate bacteria in once Fc receptors have bound to the phagocyte?

A

A phagosome.

334
Q

What happens to phagosomes?

A

They get destroyed by lysosomes.

335
Q

Do lysosomes tends to be basic or acidic?

A

Basic. They contain toxic oxygen derivatives. These are produced by increase rates of respiration.

336
Q

What do lysosomes contain other than toxic oxygen derivatives?

A

Ion binding proteins and enzymes which can break down bacterial cell walls.

337
Q

Do natural killer cells have Fc receptors?

A

Yes.

338
Q

What do Fc receptors bound to natural killer cells mediate?

A

Antibody dependent cell-mediated cytotoxicity

ADCC

339
Q

Fc receptors bind to ____ on natural killer cells?

A

IgG.

340
Q

What are natural killer cells similar to in structure?

A

C9.

341
Q

What do natural killer cells secrete?

A

Perforin.

342
Q

What process is described here?

A hollow cylinder penetrates membrane into the infected host cells. Granules in the cytoplasm are then secreted in the channel. These granules can contain enzymes. The target then undergoes apoptosis. This is better than cell lysis as enzymes are not released that could cause tissue damage.

A

The killing process of natural killer cells.

343
Q

What cell involved in the immune response has some activity against tumours?

A

Natural killer cells.

344
Q

Where are mast cells found in the body?

A

Under mucosal surfaces in tissues.

345
Q

What do mast cells contain?

A

Large specialised secretory granules.

346
Q

What type of cell mediates a defence against large parasites?

A

Mast cells.

347
Q

What receptors are found on mast cells?

A

IgE. Receptors for IgE bind to Fc receptors on the mast cells.

348
Q

The first time a mast cell becomes in contact with an antigen there is no response. What happens the second time it comes into contact with an antigen to produce a response?

A

The antigen becomes an allogen due to cross linking in the Fc receptors causing them to release granules from the mast cells in 5-10 minutes. This process is called degranulation.

349
Q

What does histamine do to smooth muscle?

A

It causes it to contract.

350
Q

In most parts of the world the response of mast cells is not needed. What is it needed more often in poorer parts of the world?

A

Parasite infections such as tapeworm are more common.

351
Q

What type of antisera is also classed as conventional antisera?

A

Polyclonal antisera.

352
Q

What can polyclonal antibodies recognise multiple of?

A

Epitopes (the part of an antigen molecule to which an antibody attaches itself.)

353
Q

Antibodies can lack specificity so are difficult to standardize. True or false?

A

True.

354
Q

Closely related antibodies can have the same shape meaning they may not only recognise the protein you want them to in an experiment. True or false?

A

True.

355
Q

How do you isolate monoclonal antibodies with single specificity?

A

B cells are taken from an animal immunised with antigen A. These are fused with a tumour cell line. The hybrid cell can only make the A antibody and divide indefinitely.
(The tumour cell line can not make antibodies.)

356
Q

Is there variation in antibody composition within the same animal?

A

Yes.

357
Q

What are ‘magic bullets’?

A

Humanized antibodies that can be used in therapy.

358
Q

Antibodies can label molecules in complex mixtures, stereotype pathogens and characterise cell surface proteins. True or false?

A

True.

359
Q

What are T cells most important in the defence of?

A

Intracellular pathogens.

360
Q

Do T cells have a memory component?

A

Yes.

361
Q

What receptor is found on a T helper cell?

A

CD4 +ve.

362
Q

What does the CD4 protein on the surface help in the production of?

A

Antibodies. (Produced by the B cells)

363
Q

What can T helper cells help devilment of?

A

T cytotoxic cells.

364
Q

What cells can T helper cells activate?

A

Macrophages and natural killer cells.

365
Q

What receptor is found on the surface on T cytotoxic cells?

A

CD8 +ve.

366
Q

What is the TCR?

A

The T lymphocyte receptor.

367
Q

What is the structure of the TCR similar too?

A

The FAB arm of the antibody.

368
Q

What four regions are found in the TCR?

A

V alpha, V beta, C alpha, C beta.

369
Q

What can B cells recognise?

A

Soluble proteins and free native antigens.

370
Q

What can T cells determine?

A

If own cells are infected.

371
Q

What chromosome contains the Major histocompatibility protein gene?

A

6.

372
Q

What two things do major histocompatibility proteins play a major role in?

A
  1. Initiating a T cell response

2. Graff rejections.

373
Q

What is the MHC?

A

The major histocompatibility gene complex.

374
Q

What are MHCI and MCHII examples of?

A

Major histocompatibility gene proteins.

375
Q

Where is the major histocompatibility gene protein MHCI expressed?

A

All nucleated cells.

376
Q

What do the MCHI display the antigen to?

A

T cytotoxic cells with the CD28 +ve receptor.

377
Q

Where is the major histocompatibility gene protein MCHII expressed?

A

Dendritic cells, macrophages and B cells.

378
Q

What do MCHII cells display the antigen to?

A

T helper cells with the CDC24 +ve receptor.

379
Q

What do Macrophages, dendtric cells and B cells have to allow the interaction with multiple T helper cells?

A

Finger like projections.

380
Q

How do T cytotoxic cells recognise in viral infected cells?

A

By the peptide bound to MHCI.

381
Q

What breaks down viral proteins in the cytosol?

A

Proteosomes.

382
Q

What happens to the viral peptides once they have been broken down by proteasomes?

A

The peptides are taken to the ER. This allows the peptide to interact with MHCI which takes it to the cell surface, displaying it to T cytotoxic cells.

383
Q

T cytotoxic cells use perforins to induce what in an infected cell?

A

Apoptosis. No toxic enzymes are produced and the dead cell can be taken up by macrophages.

384
Q

How many infectedcells can one T cytotoxic cell kill?

A

100’s. It is a very efficient process.

385
Q

What are sometimes described as ‘hormones of the immune system’?

A

Cytokines.

386
Q

Cytokines do not have autocrine or paracrine activity. True or false?

A

False. In rare occasions they can. IL1 acting with the hypothalamus to raise temperature is an example of endocrine activity.

387
Q

When a macrophage takes up a bacterium is it then infected itself?

A

No.

388
Q

In MHCII what are the peptides bound to to take them to the cell surface?

A

Endosomes. These then activate B helper cells.

389
Q

How large a cytokines?

A

5-20kd meaning they are fairly small.

390
Q

Are cytokines usually are produce and act locally?

A

Yes.

391
Q

Why are cytotoxins usually produced and made to act locally?

A

They are extremely toxic and can cause inflammation.

392
Q

What are the four main groups of cytokines?

A
  1. Interleukins.
  2. Interferons.
  3. Chemokines.
  4. Colony stimulating factors.
393
Q

Interleukins are a type of cytokine. How many types of interleukins is it thought that there is?

A

38.

394
Q

What cells usually produce interleukins?

A

T cells.

395
Q

Interferons are a type of cytokine. When are they produced?

A

When there is a viral infection. INF alpha and beta are made in this case.

396
Q

Interferons are a type of cytokine. What interferon is involved in cell activation?

A

INF gamma.

397
Q

Chemokines are a type of cytokine. What do they cause?

A

Cell movementand chemotaxis. IL8 is involved in chyemotaxis.

398
Q

What type of cytokine causes a neutrophil to move out of the blood?

A

Chemokines- these can cause cell movement.

399
Q

Colony stimulating factors are a type of cytokine. What do they cause?

A

Leukocyte production. An example of a colony stimulating factor is GM-CSF which can also stimulate T helper cells.

400
Q

Different types of cytokine can produce different types of T _____ cells.

A

Helper. More specifically TH1 and TH2.

401
Q

What is the role of TH1?

A

It can produce Inter leukins-2 gamma intefron which interacts with macrophages and TNFB which is a tumour necrosis factor. It can also cause inflammation.

402
Q

What is the role of TH2?

A

They direct antibodies to make IgE antibodies. These can fight parasitic infections and allergy.

403
Q

What can TH2 produce?

A

Interleukins (IL) 4-5-6-10-13.

404
Q

Will a person who suffers from allergies have more TH1 or TH2? Does this differ from a normal person?

A

They will have more TH2 than TH1 however a normal person will have more TH1.

405
Q

When a cytokine buds to its receptor what can it cause?

A

Cell activation and changes in gene expression.

406
Q

What type of receptors are chemokine receptors?

A

G protein coupled receptors. Many are also dimeric and enzyme coupled.`

407
Q

Where are all haemopoietic cells derived from?

A

Pluripotent stem cells.

408
Q

What are the two main linages derived from pluripotent stem cells?

A

Myloid cells and lymphoid cells.

409
Q

What two cells come from the myloid linage?

A

Plasma cells and natural killer cells.

410
Q

Platelets, granulocytes, macrophages, mast cells and dendritic cells all come from which linage?

A

Lymhoid.

411
Q

What other cell found in the blood can act as an inflammatory mediator?

A

Platlets.

412
Q

Where in the body is there high amounts of lymphnode tissue and why?

A

By the respiratory, digestive and gasteotract. There is more here as these areas are more prone to infection.

413
Q

Lymphocytes and lymph return to the blood via the _______ duct.

A

Thoracic.

414
Q

Naïve lymphocytes enter the lymph nodes from the _____.

A

Blood.

415
Q

Antigens from sites of infection reach _____ _____ via lymphatics.

A

Lymph nodes.

416
Q

What cells in the immune system take up foreign material enter the immune system and travel to the nearest lymph?

A

Dendritic cells and macrophages.

417
Q

Why can dendritic cells and macrophages present the antigens to nieve T cells found in the lymph?

A

Because they have high amounts of MCHII.

418
Q

When nieve T cells are presented with antigens from MCHII contains dendritic cells/ macrophages will they stay in the lymph to divide and differentiate?

A

Yes.

419
Q

Once the T cells have matured they leave the lymph via the efferent lymphatic vessel Where do they go?

A

The infected tissue. Compliment and innate methods are also activated in these tissues.

420
Q

What do the nieve T cells help to divide when they are presented with an antigen in the lymph?

A

B cells which then form plasma cells to make antibodies.

421
Q

Did adaptive and innate immunity coevolve?

A

Yes.

422
Q

Do adaptive responses augment or initiate innate responses?

A

Augment. Innate responses initiate adaptive responses.

423
Q

How many copies of RNA enters the cell in aids?

A

2.

424
Q

Do reteroviruses use reverse transcriptase?

A

Yes.

425
Q

When was AIDS or the HIV virus recognised first?

A

Aids. It was recognised in 1981 in California. HIV was identified in 1983 in France.

426
Q

What does the HIV virion use to stick to the host?

A

gp120 (glycoprotein).

427
Q

What part of the HIV virus enters the cytoplasm?

A

The nucleocapsid.

428
Q

When is the HIV viruses reverse transcriptase activated?

A

Once the nucleocapsid has entered the cytoplasm. The newly synthesised ds DNA can then enter the nucleus.

429
Q

Are the viral particles of HIV lytic as soon as they are made?

A

No. They are permissive when there are only a few particles.

430
Q

Are CD4+ve or CD8+ve cells susceptible to HIV infection?

A

CD4+ve (T helper cells).

431
Q

Once the CD4+ cell is infected with HIV what initially happens?

A

The infection is initially cleared. However the pool of infected cells gradually increases.

432
Q

What does activation of T cells infected with HIV also cause?

A

Virus activation.

433
Q

What can macrophages and dendritic cells also become infected with HIV?

A

They have low levels of CD4+ve on their surface.

434
Q

Why does the patient eventually die from HIV?

A

Their CD4+ cells become too depleted.

435
Q

Once HIV has infected macrophages and dendritic cells what can it do?

A

Infect the whole body via the lymph. It can also spread to T cells as these can interact with dendritic cells.

436
Q

What explains why HIV can get into the brain?

A

The fact that monocytes can become infected as these can cross the blood brain barrier.

437
Q

Is CD4+ expression sufficient for HIV infection?

A

No.

438
Q

What is needed in addition to CD4+ expression to allow the HIV virus to fuse with the host?

A

A co receptor which functions as a chemokine receptor. This was discovered in 1996.

439
Q

For a HIV virus to infect a cell the cell must express CD4+ receptors and a chemokine receptor, which acts as a co receptor. What cells in the immune system express this co receptor?

A

T cells, macrophages and dendritic cells.

440
Q

Some people are not susceptible to HIV due to mutations in their chemokine receptors. True or false?

A

True. This is common in Nordic countries.

441
Q

What do younger/ healthier people produce more off to help complete with the HIV virus, prolonging how long it takes for AIDS to develop ?

A

Chemokines. These compete with the chemokine receptors.

442
Q

What initially clears high levels of the HIV virus from the blood?

A

Mainly cytotoxic T cells.

443
Q

How long can it take for antibodies of the HIV virus to be detected?

A

3-6 months.

444
Q

What is seroconversion?

A

When a specific antibody becomes detectable in the blood, and the corresponding antigen becomes undetectable

445
Q

What type of cell is particularly important in the immune response towards HIV?

A

T cytotoxic cells.

446
Q

The HIV virus mutates to avoid CD4+ cells. True or false?

A

False. They mutate to avoid CD8+ cells (T cytotoxic cells.)

447
Q

Depletion in what type of cell causes AIDS?

A

T helper cell depletion.

448
Q

Where are cells infected by HIV found?

A

In lymphoid tissue.

449
Q

What three phases occur after infection from HIV and the before development of Aids?

A
  1. ‘Flu like disease’ (sometimes, sometimes no disease)
  2. Asymptomatic phase
  3. Symptomatic phase.
450
Q

Seroconversion happens between the asymptomatic and the symptomatic phase. True or false?

A

False. It happens between stage 1 and 2. These are the ‘flu like symptom phase’ and the asymptomatic phase.

451
Q

In what two ways can the infected T helper cells be killed?

A
  1. Cell lysis directly from the virus.

2. Other immune mechanisms eg by natural killer cells.

452
Q

Infected T cells are often found in the lymph. Why can these not be detected?

A

They are in the latent phase.

453
Q

Can Aids cause cancer?

A

Yes. in rare cases.

454
Q

When a T cell gets infected with HIV and AIDS develop, what can they activate in other cells?

A

Other latent viruses.

455
Q

A person with AIDS will not loose their T memory cells. True or false?

A

False. T memory cells are lost when someone develops AIDS.

456
Q

Can AIDS cause dementia?

A

Yes.

457
Q

What type of infection are AIDS patients most susceptible to?

A

Opportunistic.

458
Q

Where did HIV1 originate?

A

Central Africa.

459
Q

Where did HIV2 originate?

A

West Africa.

460
Q

Is HIV1 or HIV2 older?

A

HIV2. HIV1 is only 50-100 years old.

461
Q

Where was HIV1 originally found?

A

Chimps.

462
Q

HIV1 was originally found in chimps. Did the virus cause damage to these chimps?

A

No.

463
Q

Where was HIV2 originally found?

A

Sooty mangabees.

464
Q

What type of HIV has infected humans for longer?

A

HIV2.

465
Q

What type of HIV is more likely to cause AIDS?

A

HIV1.

466
Q

What is the main cause of AIDS?

A

Unprotected sex. This accounts for around 70% of cases.

467
Q

What percentage of AIDS patients caught the HIV virus via blood transmission?

A

28%.

468
Q

The HIV virus can only spread from mother to child via breast feeding. True or false?

A

False. It can also pass directly to the foetus during pregnancy.

469
Q

Why will blood testing not always detect HIV?

A

As sometimes the test will be taken before the antibodies are expressed.

470
Q

Due to error in reverse transcriptase flu mutates 60% faster than HIV. True or false?

A

False. HIV mutates 60% faster than flu due to error in reverse transcriptase.

471
Q

Why has it been difficult to develop a HIV vaccine (4 reasons)?

A
  1. There are different clades of the virus
  2. Mutation rates are high.
  3. May not protect against humoral immunity.
  4. T cytoxic cells need to be induced.
472
Q

What does azidothymidine treat?

A

Aids.

473
Q

How does azidothymidine work?

A

It acts as a nucleotide and blocks reverse transcriptase.

474
Q

What are four problems with the azidothymidine drug?

A
  1. Toxicity (as virus takes over own cells).
  2. Viral latency.
  3. Mutation rate of virus.
  4. Cost.
475
Q

What does combination therapy involve?

A

At least three drugs with different viral targets.

476
Q

Combination therapy often includes the drug azidothymidine which blocks reverse transcriptase. What 3 types of inhibitors are also often found in combination therapy?

A
  1. Other reverse trascriptase inhibitors.
  2. HIV protease inhibitors.
  3. Fusion inhibitors.
477
Q

Has combination therapy been successful?

A

Yes. In the west.

478
Q

What would passive immunisation against HIV involve?

A

Using human monoclonal antibodies in the vaccine.

479
Q

What would gene editing to treat HIV involve?

A

A bone marrow transplant from someone who could not express the needed chemokine receptor.

480
Q

What does the ‘kick and kill’ method to treat HIV involve?

A

Reactivating latent virus cells with combined immunotherapy so they can be killed by the patients own T cells.

481
Q

What are the three reasons why eukaryotic genomes are much harder to sequence than bacteria/ archaea genomes?

A
  1. They are much larger.
  2. They contain uncoded DNA.
  3. There are often duplicated copies of genes.
482
Q

What process do eukaryotic cells go through in order to loose structures?

A

Reductive evolution.

483
Q

What are the 3 main groups of eukaryote?

A
  1. Opisthokonta
  2. Viridaplantea
  3. Protists.
484
Q

Opisthokonta are a main eukaryotic group. What do they contain?

A

Fungi and animals.

485
Q

What main eukaryotic group contains primary algae and green plants?

A

Viridaplantea.

486
Q

The protists are a main eukaryotic group. What do they contain?

A

Algae that have undergone secondary symbiotic events.

487
Q

There is the greatest diversity of size and shape in eukaryotes than in the other domains of life. What is the less diversity in?

A

Metabolism.

488
Q

What does the name ‘Opisthokonta’, the group of eukaryotes dedicated to fungi and animals, refer to?

A

The backwards pointing flagellum found in the sperm of animals and zoospores of fungi.

489
Q

The word ‘opishokonta’ refers to backwards pointing flagellum contained by the group members. Do all fungi have this flagellum?

A

No, due to reductive evolution. Some fungi are now non motile but at some point they would have had them.

490
Q

What is thought to be the missing link between multicellular eukaryotes and multicellular fungi?

A

Choanoflagellates ( a type of eukaryote) are very similar to chanocytes found in sponges.

Nb. choanoflagellates can be grouped to form sponges.

491
Q

Modern genetic analysis has caused some fungi to be regrouped as what?

A

Protists.

This includes slime and water moulds.

492
Q

Microsporidians used to be classified as protists however they have now been moved into the Opistokonta group. Why is this?

A

They contained a highly conserved peptide sequence only found in animals and plants.

493
Q

Where did primary endosymbiotic algae come from eukaryotes that had already developed a mitrochondria or eukaryotes that had already developed chloroplasts?

A

Eukaroytes that had already developed a mitochondria.

494
Q

What do primary endosymbiotic algae use cyanobacteria for?

A

Feedstocks.

495
Q

What rare event would have taken place to allow a symbiotic relationship to form between primary endosymbiotic algae and cyanobacteria. What was formed as a result of this event?

A

The cyanobacteria cell wall would not have been digested properly -this would have caused a chloroplast to form.

496
Q

What indicates the development of a symbiotic relationship between primary endosymbiotic algae and cyanobacteria?

A

The double membrane surrounding the chloroplast.

One of these membranes would have come from the cyanobacteria and one would have come from the food vacuole.

497
Q

What event happened to cryptophyte algae?

A

A second endosymbionant.

498
Q

Cryptophyte algae have two nucli due to a second endosymbiotic event. What did they engulf in this second event?

A

An algal cell.

499
Q

Due to a second endosymbiotic event in cryptophyte algae they have two nuclei however the one taken up via the algal cell is inactive. What is this inactive nuclei called?

A

A nucleomorph.

500
Q

What are Chlorophyta also known as?

A

Green algae.

501
Q

What are Chlorphyta very similar to?

A

Plants.

502
Q

What is Chlamydomonas reinhardtii classes as?

A

A green algae.

503
Q

Is C. reinhardtii, an example of a chlorophyta, uniceulluar or multicellular?

A

Unicelluar.

504
Q

C. reinhardtii has 2 ____ flagella at the ______ (front) end of the cell. They move by using a _____ ______ swimming actin.

A

Equal, anterior, breast stroke.

505
Q

The cell ultrastructure of the Chlamydomonas is typical

of algal cells. What are the cell walls made of?

A

Cellulose and glycoproteins.

506
Q

What is most of a typical algae cell made up of?

A

One large chloroplast.

507
Q

Is cytoplasm at the end closest to the flagella in an algae cell?

A

Yes.

508
Q

A pyenoid is fully surrounded by the chloroplast at one end of the algae cell. What is this for?

A

The pyenoid concentrates CO2 for fixation.

509
Q

The pyenoid in an algae cell is directly surrounded by a starch body. What is the purpose of this starch body?

A

Energy storage.

510
Q

Although the genetics of most algae are not well understood, they are for Chlamydomonas. reinhardtii (a type of chlorophyta). Do they have a haploid cycle for asexual and sexual reproduction or is only the asexual cycle haploid?

A

Both cycles are haploid. They will sexually reproduce if two mating types meet.

511
Q

What other algae which has no cell wall looks like C. reinhardtii?

A

Dunaliella.

512
Q

Dunaliella and C.reinhardtii are both unicellular algae. Which one is also halotolerant?

A

Dunaliella.

513
Q

Recently there has been a number of newly discovered picoeukaryotes which are only 0.5um to 3m in size. What are they classed as?

A

Chlorophyta (green algae).

514
Q

What is Ostereococcs tauri an example off?

A

A picoeukaryote, which is also a type of green algae.

515
Q

What are Rhodophyta also known as?

A

Red algae.

516
Q

Rhodophyta are unicellular algae. True or false?

A

False. They can be unicellular or filamentous/ multicellular. Green algae however are all unicellular.

517
Q

Where are Rhodophyta often found?

A

They are often found in association with seeweed.

518
Q

Why are Rhodophyta often found in association with seedweed?

A

They provide important compounds that can be used as gelling agents. These include agar and agarose.

519
Q

What is the name of the pigment that cause Rhodophyta to be red?

A

Phycoerythrin.

520
Q

The pigment phycoerythin causes Rhodophyta to be red. Where is this pigment also found?

A

In cyanobacteria, however it is not similar in them.

521
Q

Are red or green algae often used as foodstuff?

A

Red algae (Rhodophyta) are often used as foodstuff. This includes Nori in Japan and Laverbread in Wales.

522
Q

Are red or green algae associated with higher plants?

A

Red.

523
Q

The protists contain a mixture of groups which used to be divided into what?

A

Algae and protozoa.

524
Q

What two traits separate secondary endosymbiotic algae with primary endosymbiotic algae?

A
  1. They have at least two membranes around their chlorophyll.
  2. They use a mixture of mixotrophy and heterotrophy.
525
Q

What can primary endosymbiotic algae catabolise?

A

Simple substrates such as acetate, glycerol and glucose.

526
Q

What type of organism is very widespread but not yet categorised?

A

Hapophytes.

527
Q

What major group is responsible for at least 20% of the Earths photosynthesis?

A

Diatoms.

528
Q

What larger eukaryotic group do the Diatoms fall into?

A

Protists.

529
Q

Diatoms have overlapping frustules. What are these?

A

Very tough silica cell walls. These cell walls produce diatomaceous Earth.

530
Q

What happens in asexual reproduction in Diatoms which must be reserved by sexual reproduction?

A

A reduction in size.

531
Q

What are the two major forms of Diatoms?

A

Centric and Pennate.

532
Q

What is the difference between Centric Diatoms and Pennate diatoms?

A

Centric diatoms have radical symmetry and Pennerate diatoms have radical symmetry.

533
Q

Seeweeds are what type of algae?

A

Brown/ Phaeophyceae.

534
Q

How long can Phaeophycee algae be?

A

70km. They can also form kelp forests.

535
Q

Apart from from foodstuffs, why else would you harvest brown/ phaeophycee algae?

A

They provide a source of iodine.

536
Q

Brown algae posses vacuoles of oily liquid for energy storage. What is the liquid called?

A

Leucosin.

537
Q

What is an example of an Haptophyte?

A

Coccolithophores such as Emilania huxleyi.

538
Q

What do Coccolithopores, an example of an haptophyte, produce to protect them from predators?

A

An exoskeleton of coccoliths made of calcium carbonate.

539
Q

What can Coccolithopores absorb lots of

A

CO2.

540
Q

What can E. huxleyi form which go on for thousands of km?

A

Ocean blooms. The cause of these blooms is currently unknown and it is difficult to recreate them in a lab. If more is found out, especially in regards to the side effects, they could be used to help combat climate change.

541
Q

What are dinoflagellates an example off?

A

Secondary endosymbiotic algae.

542
Q

Dinoflagellates are an example of secondary endosymbitoic algae, however they are grouped with the aveolates. Why is this?

A

They have alveoli.

543
Q

Why do Dinoflagellates move with a swimming motion?

A

Because their flagella are very different in length. these are known as transverse and longitude.

544
Q

Several species of what organism are toxic, producing red tides in coastal waters?

A

Dinoflagelattes.

One example of a toxic form is Gonyaulax.

545
Q

How are Alveolates grouped together?

A

Based on flattened vacuoles (alveoli) beneath their membrane.

546
Q

Paramecium is an example of a Cilitate. What group is this included in?

A

Alveolates.

547
Q

Paramecium is an example of a Ciltate with is classed as an Alveolate. It has two nuclei. What can this generate?

A

The diploid micronucleus can generate a macronucleus which has many copies of DNA for gene expression.

548
Q

Paramecium contains two nuclei. Does the micronucleus, macronucleus, or both take part in conjuction?

A

Only the micronucleus.

549
Q

What where Apicomplexans formally known as?

A

Sporozoa.

550
Q

What are Apicomplexans?

A

A parasite. This includes P. falciparum.

551
Q

What unique organelle do Ampicomplexans contain which was originally derived from the endosymbiotic chloroplast?

A

The apicoplast. It has no photosynthetic activity remaining but it is still essential.

552
Q

What do Ampicomplexans have to allow them to enter the host cell?

A

An apical complex.

553
Q

What do Amoebas use to move?

A

Pseudopodia.

554
Q

Amoebas use Pseudopodia to move. How does this work?

A

They flow via a gel-sol transition based on actin polymerisation.

555
Q

Amoebas are harmful and other cause dysentery. True or false?

A

False. Most amoebas are harmless. Only Entamoeba histolytica causes dysentery.

556
Q

Slime moulds are amoebas that aggregate in their thousands into a complex fruiting body. What does this resemble?

A

A fungal fruiting body.

557
Q

What acts the aggregation molecule in slime mould formation?

A

cAMP.

558
Q

What is Dictyostelium an example off?

A

A cellular slime mould (this means that the individual cells remain cellular.)

559
Q

In a cellular slime mould individual cells remain cellular. What is he other type of slime mould where the cells become a giant multinucleate structure?

A

Plasmodial.

560
Q

What is Euglenozoa (eg Euglena) an example of?

A

A Secondary endosymbiotic algae.

561
Q

What can happen to Euglenozoa?

A

It can loose its flagella completely and grow heterotrophically.

562
Q

What are some Euglena ?

A

Acid tolerant. They can grow in the acid tar lagoon in North West England which has an average ph of 2.6.

563
Q

What caused acid tar lagoons.

A

62,000 tons of liquid oil refinery waste was poured into an exacutaved clay pit which was 9m deep.

564
Q

Is the acid lagoon in north west England the only one of its kind?

A

No, they are a world wide problem.

565
Q

Euglenoza include Egulena, an organism that can survive in acid tar lagoons. What other major organism is part of the Euglenoza class?

A

A group of obligate parasites called trypanosomes.

566
Q

Trypanosomes are a parasite and are part of the Eugulenozoa group. What illness can they cause?

A

Sleeping sickness.

567
Q

What mainly are the class of organism Metamonda?

A

Parasites.

568
Q

Metamonda (such as Giardia lamblia) have lost what through degenerative evolution?

A

Mitochondria.

569
Q

Apicomplexans contain a apicoplast derived from a chloroplast. Are they photosynthetic?

A

No.

570
Q

What is Dictyostelium an example off?

A

A cellular slime mould.

571
Q

Does the Euglenozoa group contain PEA or SEA?

A

SEA.

572
Q

Metamonda have undergone degenerative evolution and have lost their chloroplasts. What other organelle do they not have?

A

Golgi bodies.

573
Q

Microbes recycle _______ material in _______ and ________ ecosystems. This provides resources for ________ _________.

A

Organic, aquatic, terrestrial, higher organisms.

574
Q

What is an ecosystem?

A

A population of species (often called a community of species) plus their habitat or environment.

575
Q

What is a nieche?

A

A subset of conditions enabling an organism to grow and reproduce.

576
Q

What two things make lakes a good ecosystem to study?

A
  1. They are self contained

2. They have many nieches.

577
Q

Van Niel described two main principles of ecology. What where these?

A
  1. Every molecule existing in nature can be used as a carbon and energy source for a microbe somewhere on Earth.
  2. Microbes are found in every environment on Earth.
578
Q

Does the total volume of anerobic microbial community exceed that of the oxygenated biosphere?

A

Yes.

579
Q

How far below the Earths surface have microbes been found?

A

3km.

580
Q

What process is performed by primary producers?

A

Assimilation.

581
Q

What is dissimilation?

A

Breakdown of organic nutrients to inorganic materials eg CO2 and NO2-.

582
Q

What three things can be used to calculate biomass?

A
  1. Cell number
  2. Wet weight
  3. Dry weight
583
Q

What do microbial food webs consist off?

A

Primary produces, grazers, predators, secondary predators.

584
Q

What is parasitism?

A

A microbe benefits at the expensive of another microbe in a very specific manner?

585
Q

What is amensatism?

A

A microbe benefits at the expense of another in a non specific manner.

586
Q

What is commensalism?

A

A microbe benefits, but has no discernible impact on another species.

587
Q

What is mutualism?

A

Both species benefit and may not grow independently.

588
Q

All microbes can be cultured. True or false?

A

False. Some need very specific nutrients, physical conditions and the presence of other microbes.

589
Q

Not all microbes can be cultured. What two methods are available to overcome this problem?

A
  1. DNA sequencing.

2. Environmental samples.

590
Q

Some microorganisms survive better on agar. True or false?

A

True.

591
Q

What environment has the largest diversity of organisms by far?

A

The soil.

592
Q

What environment has the lowest amount of diversity and why?

A

The air, this is because it lacks nutrients.

593
Q

What is the name given when all genomes in a particular community are represented?

A

A metagenome.

594
Q

What are the 6 steps involved in producing a metagenome?

A
  1. Ecosystem is sampled.
  2. Filter/ concentrate the sample.
  3. Break open the cells without breaking the DNA.
  4. Clone DNA with PCR.
  5. Read DNA sequence.
  6. Build scaffolds and sample genomes.
595
Q

Why are 16s RNA genes used in forming a metagenome in prokaryotes and 18s RNA genes used in forming a metagenome in eukaryotes?

A

As they are highly conserved.

596
Q

What is the term ‘operational taxonomic units’ used instead of species during the formation of a metagenome?

A

Because it is unknown if each band is a species.

597
Q

How can you estimate community diversity?

A

By plotting operational taxonomic units (OTUs) identified against the number of species. This levels of in water and air samples but not soil.

598
Q

If there is more than _____ difference and less than ______ similarity between bands they are then classed as a different species.

A

3%, 90%.

599
Q

What environment, other than air has a small species diversity?

A

Extreme environments. The acid tar lagoon only has 50-60 species present in it.

600
Q

Through technological advancements producing a metagenome is now relatively cheap. True or false?

A

False.

601
Q

Is forming a metagenome or culturing organisms more important?

A

Culturing an organism.

602
Q

What can be used to find microbes of interest in a culture?

A

Changed physical conditions such as pH or carbon source.

603
Q

What can microorganisms provide through reducing organic minerals?

A

Resources for higher organisms.

604
Q

What is an ecosystem?

A

A population or species and their habitat/environment.

605
Q

What is a nieche?

A

A subset of conditions enabling an organism to grow and reproduce.

606
Q

Why are lakes mainly nieches?

A

They are self contained.

607
Q

What can microbes do to provide resources for higher organisms?

A

Reduce organic material.

608
Q

What is an ecosystem?

A

A population of species plus their habitat.

609
Q

What is a nieche?

A

A subset of conditions enabling an organuism to grow and reproduce.

610
Q

Why are lakes good nieches?

A

they are self contained.

611
Q

Who formulated the two key points of microbiology?

A

Van Neil.

612
Q

What two points did Van Neil come up with?

A
  1. Every molecules in nature can be sued as a carbon and energy source by some form of microbe somewhere on Earth.
  2. Microbes are found in every environment on Earth.
613
Q

What exceeds the total volume of oxygenated biosphere?

A

The total volume of anerobic biosphere.

614
Q

How far below the surface have microbes been found?

A

5km.

615
Q

No microbes can grow more than 5km below the surface. true or false?

A

False. it is not known as further depths have not been sampled.

616
Q

What type of producer allows for assimilation?

A

Primary.

617
Q

What is dissimilation?

A

The breakdown of organic nutrients to inorganic minerals such as carbon dioxide and NO2-.

618
Q

What is the definition of biomass?

A

Bodies of living organism. Cell number, wet mass and dry mass can be used.

619
Q

Each environemnt can support a certain amount of biomass. true or false?

A

True.

620
Q

Do foodw ebs exist in the microbial world?

A

Yes.

621
Q

What is the definiton of parasitisum?

A

When a microbe benefits at the expensive of another microbe in a very specific manner.

622
Q

What is the definition of amensalism?

A

When a microbe benefits at the expensive of another microbe in a non specific manner.

623
Q

What is the definition of commensalism?

A

When a microbe benefits of another but has no impact on the other organism.

624
Q

What is the definition of mutualism?

A

Both species benefit and may not grow independently.

625
Q

How much of the Earths surface do oceans cover?

A

2/3.

626
Q

What are the primary produces in ocean ecosystems?

A

Microbes. On land these are plants.

627
Q

What is the iopen ocean water column also called?

A

The pelagic zone.

628
Q

What is the neuston?

A

Where the water meeets the air.

629
Q

How thick is the neuston?

A

10 micrometres.

630
Q

How far down does the euphotic zone reach?

A

200m metres although is is variabke depending on organims above and poluttion.

631
Q

What can the euphotic zone recieve?

A

Light.

632
Q

What lives in the aphoitic zone?

A

Hetereotrophs and lithotrophs.

633
Q

What is special about the photic zone?

A

it can not receive light.

634
Q

what is the oicean floor also be known as?

A

The benthos.

635
Q

The benthos is in the deep ocean. True or false?

A

False. it is just the ocean floor so can also be shallow.

636
Q

The opean ocean can be described as oligotrophic. What does this mean?

A

It is low in nutirents.

637
Q

What can cause more growth on coastal shelf?

A

Sewage columns.

638
Q

What are microplankton?

A

20-200um large cilliated protists and algae.

639
Q

What are nanoplankton?

A

2-20um in size, smaller algae and flagellated protists. Also includes fillamentous bacteria.

640
Q

WHat are picoplankton?

A

0.3-2um in size. Bacterial phototrophs, hetereotrophs and lithotrophs. All prokaryotes.

641
Q

What can microrganisms use to float?

A

Gas vesicles and flagella.

642
Q

Why does the coastal shelf have the highest concerntration of microorganims

A

As it has the highest concentration of nutrients.

643
Q

Why is the light penetration lower on the coastal shelf than in the open ocean?

A

There is a higher concentration of microorganisms.

644
Q

What has the shallow photeic zone have less off?

A

Diversity in microorganisms.

645
Q

What can not normally be cultured in labs with standerd techniques?

A

Marine microorganims.

646
Q

The metagenome allows all marine microorganisms to be cultured. True or false?

A

False. It still can miss some.

647
Q

How can a measure of expressed genes from an ecosystem be given?

A

A megatranscriptosome of mRNAs can be transcribed into cDNA and then amplified/ sequenced.

648
Q

What genes were rarely in the metagenome?

A

Highly expressed genes.

649
Q

What did 40% if expressed genes in the metagenome not have?

A

A match to genomic DNA.

650
Q

What was the most transcribed in the metagenome?

A

Lowest abundant DNA. This showed that many organism were missed in the metagenome.

651
Q

Who went on the Socrecer II Expedition?

A

Craig Venter.

652
Q

When did Craig Venter go on the Sorcerer II Expedition?

A

2003-2004.

653
Q

Where did Craig Venter sail on his expedition?

A

Down the east coast of the US, though the Panama Canal, along the coast of South America and then to the Galápagos Islands.

654
Q

How often did Craig Venter take a sample?

A

Every 200 miles.

655
Q

What depths were mainly sampled on the Sorcerer II expedition?

A

1-5m. Some coastal samples would have been 10-100m and some deep samples would have been up to 4500m.

656
Q

How many samples were taken another by Craig Venter?

A

44.

657
Q

Craig Venter made the samples fair by using the same sample size. True or false?

A

False. 20-0.1um pore sizes were used.

658
Q

What temperature were the samples stored at on the Sorcerer II expedition?

A

-20 degrees.

659
Q

How long did Craig Venters expedition take?

A

2 years.

660
Q

Where did most of the sequence data come from after the Sorcerer II expedition?

A

The smallest size organisms. These were mainly archaea and bacteria.

661
Q

What technique was used to sequence the samples taken on the Sorcerer II expedition?

A

Shotgun sequencing.

662
Q

How much of the sequenced DNA found on the Sorcerer II expedition matched known samples?

A

30%.

663
Q

What was one of the most abundant strains identified from the Sorcerer II expedition?

A

Pelagibacter.

664
Q

What do Pelagibacter use?

A

Proteorhodopsin.

665
Q

What is Synechoccocus also a type off?

A

Cyanobacteria. These along with Prochloroccus were highly abundant.

666
Q

What is a special feature of Prochlorococcus?

A

They are extremely small even compared to prokaryotes. They are the smallest known oxygenic phototroph. 0.5-0.7um.[

667
Q

What are Prochlorococcus?

A

A dominant photoautotroph in ocean surface waters. One of the most dominant organisms on earth.

668
Q

What organisms contains unique divinyl chlorophyll and no phycobilisomes?

A

Prochlorococcus.

669
Q

It is difficult to isolate Prochlorococcus. True or false?

A

False. They are easily isolated and grown.

670
Q

How large is the genome of Prochlorococcus?

A

2000 genes so it is small.

First year (10 decks)

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