Microbiology semester 1 Flashcards
(289 cards)
1
Q
Arthopods need a microscope to be seen. Are they microbes?
A
No.
2
Q
What is the size range of a microbe?
A
mm to 0.2um.
3
Q
How much smaller are viruses then microbes?
A
10 times smaller.
4
Q
Why can microbes divide quickly?
A
They have few internal membranes.
5
Q
What can microbes, such as mushrooms and kelps form?
A
Multicelluar assembleges.
6
Q
What do multicellular assembleges contain?
A
Differentiated cells with a particular function.
7
Q
What did Carl Woese do?
A
Proposed the three domains.
8
Q
The earliest form of life comes form bacterial communities called ________.
A
Stromatalities.
9
Q
How old are stromatalites?
A
3.4 billion years old.
10
Q
What can the outermost organisms on stromatalites do?
A
Photosynthesise.
11
Q
What do the inner most organisms in a stromatalite do?
A
They support sulphur reducing bacteria.
12
Q
Would rubisco rather fix C12 or C13?
A
C12.
13
Q
Rocks depleted of C13 show evidence for what?
A
Early life.
14
Q
How far can isotopic ratios date back life to?
A
3.8 million years.
15
Q
What are the 8 elements required for early life?
A
C, H, N, O, Mg, Fe, K, Ca.
16
Q
What was the temperature thought to be on early Earth?
A
Between the freezing and boiling point of water. It could have varied due to pressure.
17
Q
What two things could have provided an energy source on early Earth?
A
Sunlight and reduced minerals.
18
Q
What could early cyanobacteria do?
A
Split water into oxygen.
19
Q
Evidence of oxygen in the atmosphere comes from the oxidation of what?
A
Iron.
20
Q
What iron form is soluble.
A
Fe2+.
21
Q
What can Fe3+ form?
A
Precipitates.
22
Q
What oxidised Fe2+ to Fe3+ on early Earth?
A
Chemolithrophs.
23
Q
Chemolithotrophs could oxidise Fe2+ using the oxygen produced from what organism?
A
Cyanobacteria.
24
Q
Where could have BIFS directly arose from?
A
Anaerobic photosynthesis with FE2+ acting as the electron donor.
25
What could have occurred in cycles until all the marine oxygen was used up?
Photoferrotrophy.
26
What is the most convincing evidence of early life?
Microfossils.
27
What do convincing microfossils need to show?
A regular 3D pattern.
28
Why are archean microfossils less regular?
Because most of the rock was metamorphic allowing it to be greatly modified by temperature and pressure.
29
What is a biosigniture?
A chemical indicator for life.
30
Although some biosignitures date earlier than fossils why is it difficult to say this is proof for earlier life?
As it is hard to rule out nonbiogenic explanations for the production of biosignatures.
31
What is a hopanoid an example of and why?
A biosignature as it is only produced by bacteria.
32
What hopanoid derivative was found in sedimentary rock in western Australia?
2 methlyopane.
33
What does the presence of hopanoids and its 2 methylopane derivative allow you to conclude?
That some bacteria were present at the end on the archean eon.
34
What is the 'Metabolists Model'?
Metabolism forming simple organic compounds then more complex compounds with nucleic acids evolving later.
35
The metabolism of what compound is the bases of the 'Metabolists Model' theory?
CO2.
36
How does the 'Metabolists Model' propose how CO2 metabolism originated?
Through self sustaining reactions.
37
What is it possible to spontaneously form from water and carbon dioxide?
Acetate (C2).
38
What could early pathways forming simple organic molecules be promoted by?
Minerals and porous surfaces acting as catalysts.
39
What could catalyse carbon fixation in the 'Metabolists Model'?
FeS. This is a self sustaining reaction. These iron centres are still found in the electron transport chain.
40
What can CO2 be abiotically polymerised into?
TCA cycle intermediates.
41
Where does the 'Metabolists Model' propose amino acids came from?
Intermediates of the TCA cycle.
42
The 'Metabolists Model' proposes that each amino acid originally came from a TCA cycle intermediate. What does it propose then happens to the amino acids?
The amino acid would be complexed into a dinucleotide forming the first two amino acids of a codon. This explains why most amino acids with specified by a codon starting with the same 2 nucleotides are synthesised from the same TCA cycle intermediate.
43
Do all models of early life depend upon the formation of an enclosed space?
Yes.
44
Why can fatty acids spontaneously form micelles?
They are ampiphillic.
45
What can micelles form under certain conditions?
Hollow vesicles of membrane that can take up molecules such as RNA.
46
What is 'RNA world'?
The theory that nucleotides arose spontaneously and formed RNA. This catalyses the chemical reactions needed to form genetic material.
47
Is DNA or RNA proposed as the first information molecule?
RNA.
48
Does it require less energy to form and degrade RNA than DNA?
Yes.
49
Is uracil or thymine easier to form?
Uracil. This is proven by the fact that it is formed earlier in the biochemical pathway.
50
What is a ribozymes?
RNA with enzymatic processes which can also cleave itself and synthesise complementary RNA strands.
51
One of the key steps in protein synthesis is peptide bond formation, which is catalysed by peptidyl transferase activity found where?
The ribosomal RNA. This is another reason in which RNA world is currently the number one theory about the origin of life.
52
Why is it thought that DNA took over from RNA as the genetic material?
It is more stable.
53
Why is it unknown if RNA world would work?
Because the temperature on early earth was unknown.
54
Do we know the role of methane on early Earth and the source of the first cell?
No.
55
What is the difference between panspermia and neopanspermia?
Panspermia is the theory of origin of life form space and neopanspermia is the theory that life continuously comes to Earth from space.
56
How big where the balloons used by Hoyle and Wickramasingme in 2000?
30km.
57
How much did each balloon launch cost?
£500,000.
58
How high up was life found by Hoyle and Wickramasingme in 2000?
41km up.
59
What did Chris Rose and Alex Baker use instead of balloons in 2014?
Highly sterile sampling drawers.
60
How much did the sampling drawers cost?
£3000.
61
What did Chris Rose and Alex Baker find?
New stratospheric particles of 30um 27km up.
62
What did the new particle, discovered by Chris Rose and Alex Baker, have a structure off?
A diatom.
They also found a Proboscis and Sphincter and Sheild particles. They came in at speed as the sample tray was damaged. One sample also contained a surface covered in fillaments/ knitted mycelium and bifurcating filaments.
63
How long where the samples taken after volcanic eruptions?
2 years.
64
If no volcanic eruptions have taken place in the last two years, what is the biggest size particle able to float up into the stratosphere?
5um.
65
What was used to examine the particles?
A scanning electron microscope and EDX.
66
Do algae cause disease?
No. They cause toxic blooms.
67
are septicaemia and meningitis caused by bacterial or viral infections?
Bacterial.
68
Who came up with 'miasma'?
Van Leeuwenhoek. He looked at bacteria on teeth and added water which he used as an extra lens.
69
What did Lady Montague Wortley find?
She went to Turkey and found that they were inoculating with small pox.
70
Who introduced vaccination?
Edward Jenner and Bejamin Jetsy. Used cowpox to inoculate with small pox.
71
What did Semmelweis do?
Made people wash their hands. He thought disease was caused by dead flesh.
72
What did Louis Pasteur disprove in the 1860s?
Spontaneous generation. He proved that microbes came from the air.
73
What is Kochs postulate?
1. Disease is caused by a single organism.
2. You can get this organism by isolating it from a person with the disease.
3. If you take the organism and inject into an animal/human they will get the disease.
74
Who came up with Antiseptic surgery?
Lord Lister.
75
Is antiseptic surgery used today?
No - aseptic surgery is.
76
What did Paul Ehrilch discover?
Salversan 606.
77
What did Salversan 606 kill?
Siffalysis.
78
What did Hazen and Brown discover?
Nystain which can treat thrush.
79
What did Marshell and Warren prove in the 80's?
That bacterium caused stomach ulsers.
80
What is heterotophy?
Energy is obtained by breaking down preformed carbon via respiration.
81
What is autotrophy?
Energy is gained by performing chemical reactions. Carbon is fixed from carbon dioxide in the air.
82
Plants take up nitrogen in which two forms?
Nitrate or ammonium.
83
What step in the nitrogen cycle involves converting organic nitrogen into ammonium in most aerobic and anernobic bacteria?
Ammonification.
84
What is nitrification an example of?
Chemoautotrophy.
85
In nitrification what do nitrosomonas oxidise ammonium to?
Nitrite.
86
In nitrification what do nitrobacter oxidise nitrite too?
Nitrate.
87
In denitrfication is nitrate oxidised or reduced into nitrogen gas?
Reduced.
88
What conditions does denitrificaiton happen in?
anaerobic.
89
What type of bacteria can carry out denitrification?
Heterotrophic.
90
What stage in the nitrogen cycle is utilized to covert urea into a safe waste gas?
Denitrification.
91
What stage of the nitrogen cycle can be abiotic or symbiotic?
Nitrogen fixation.
92
What bacteria is found in the root nodules of leguminous plants, forming a symbiotic relationship with the plant by fixating nitrogen?
Rhizobium.
93
Each plant produces an attractant specific to a certatin rhizobium, attracting that rhizobium and causing a mutualistic symbiotic relationship to form. What does the rhizobium gain form the plant?
Sugar.
94
When rhizobium infects the plant is there a specify infection process?
No.
95
Rhizobium infects the plant via a crack in the _____. They then multiple greatly forming a ______ which the plant then lays down a _______ around.
Root, bacteroid, nodule.
96
What type of bacteria are involved in abiotic nitrogen fixation?
Azotobacter. These live in soil and are also point in soil to increase its nitrogen content.
97
Who was involved in the production of the first sewer?
Sir John Bazelgette.
98
The first sewer was found in London. What shape was it?
Egg shaped.
99
The first sewage system resulted in solids forming on the bottom and liquid forming above this. Where are the anaerobes found?
In the solid. Aerobes are found in the liquid.
100
What are filter beds made from?
Stone or coke.
101
What is the structure of a filter/contact bed?
Round with a rotating arm in the middle.
102
Filter beds only contain aerobic microbes. True or False?
False. They contain aerobic and anaerobic microbes.
103
What is the most effective sewage process?
The activated sludge process.
104
What is the brush for in the activated sludge process?
To remove large objects.
105
What is the buffled tanked made out of in the activated sludge process?
Concrete.
106
The first tank in the activated sludge process is the aeration tank. What is the second block?
The anerobic digester, also known as the clarifier. Carbon dioxide, energy and methane are removed here. Methane is then purified and can be used to power the sewage or is sold.
107
What does a membrane coliform count involve?
Testing water for bacteria.
108
What does BOD stand for?
Biological oxygen demand. The oxygen content of water is checked over a few days to ensure the absence of microbes.
109
What type of organism causes wilt disease on plants?
Fungi. This fungi alters the xylem meaning water can not be correctly transported around the plant.
110
What percentage of crops are lost to disease?
1/4.
111
How do fungi spread?
Spores. It is the spores that are the infective agent. Fungi can spread through air and water.
112
What organism causes post harverst deterioration?
Fungi.
113
How are zoospores transmitted?
In water.
114
Fungi enter the plant through the _____ . They germinate to form an _________ . _____ _____ is produced first and forms a _______ _______ structure. The ________ pushes down under the leaf and produces a ________. The contents of the ________ is squeezed into the ______ causing the infection. The _______ increases the surface area for infection.
1. Leaf
2. Appressorium
3. Germ tube
4. Boxing glove
5. Appressorium
6. Stylet
7. Appressorium
8. Leaf
9. Haustorium.
115
In what three ways can a plant fight back against an infection?
1. Waxy surface/ surface hairs.
2. Infection enclosed by a layer of cork.
3. Phytoalexins produced.
116
Monoculture is often used in the US. It allows quick spread of infection. Why is it still used?
It is the best way to produce a large volume of food.
117
What are copper salts and Benomyl examples of?
Fungicides.
118
Bordeux mixture is used to prevent fungal infection in humans. What is it made from?
Lime and copper sulphate.
119
Are fungal infections pathogenic?
No. They are opportunistic.
120
What is the main cause of death in aids patients?
Fungal infections.
121
Saprophytes need an opportunity to grow. What is the definition of a saprophyte?
A plant, fungus, or microorganism that lives on dead or decaying organic matter.
122
Dermatophytes are opportunistic filamentous fungi. What can they cause?
Skin infections. They also cause itching.
123
How do Dermatophytes break down skin?
They break down the keratin by producing keratinases.
124
Where can a Dermatophyoses be caught from?
Soil or pets.
125
Athletes foot and ringworm are caused by Dermatophytes. They are now treated with antibiotics. What did they used to be treated by?
Seritan violet stain.
126
What do mucosal yeasts effect?
The mucus membranes (eg in the throat, vagina and anus.)
127
What sort of infection is common in newborns?
Ones caused by mucosal yeasts.
128
When an infection is spread throughout the whole body what is it said to be?
Systematic.
129
What can mucosal yeasts occasionally produce to make them dimorphic?
Mycelium.
130
What is a latrogenic infection?
An infection caused by medical intervention. This includes the contraceptive pill which can cause a hormone imbalance.
131
Are mucosal yeasts a type of venereal disease?
No. But they can be spread by sex.
132
Where do systemic mycoses infect?
Inside bodies.
133
Aspergillus fumigatus (farmers lung) and Blastomyces blastomycis are examples of what?
Systemic mycoses.
It is possible for blastomyces blastomycis also to come out the body and infect the skin.
134
Where in the world is Blastomyces blastomycis, an example of a systemic mycoses, found?
The southern US states.
135
Madura foot is found in the Indian subcontinent. What is it an example of?
Mycetoma.
136
What type of antibiotic is Nystain?
An antifungal antibiotic.
137
Amphotericin B is now used to treat systemic fungal infections. Why was it not used in the past?
It has very bad side effects.
138
Are there any antifungal immunization vaccines?
No.
139
What does the antibiotic Griseofulvin treat?
Dermatophyte skin infections.
140
Apart from Nystain, what other antibiotic can be used to treat thrush infections by mouth or by cream?
Fulconazole.
141
What does MRSA stand for?
Methicillian Resistant Staphylococcus Aures.
142
What is Methicillian?
A broad spectrum antibiotic.
143
What can MRSA cause?
Septicemia.
144
What antibiotic is being used as a 'last resort', although resistance for this is also developing?
Vancomycin.
145
What is the definition of biotherapy?
The use of living organisms in the treatment of disease.
146
If a chemical from a living organism is used to treat a disease is this classed as biotherapy?
No.
147
What can maggots and blowflies be used to treat?
Long standing indolent wounds. These wounds are often on the legs and are due to diabetes.
148
What do maggots do when they are applied to an infected wound?
They produce antibiotic agents and will consume infected meat and stop at the bone. The antibiotic agents can heal the wound.
149
Why is it more beneficial to apply the maggot directly to the indolent wound instead of purifying the antibiotic produced by them?
As the maggot also cleans away the infected flesh by consuming it. If you just purified the secreted antibiotic you would not get the full effect of the process.
150
What causes half of soft tissue and skin infections in the USA's intensive care?
MRSA.
151
Who developed 'modern maggot therapy?'
William Stevenson Bear.
152
What is 'modern maggot therapy' now called?
Debridement therapy.
153
What is used to ensure that the maggots go all the way to the bone in debridement therapy?
Lightbulbs. The maggots will move away from the light meaning they will end up going deeper into the body.
154
Why do sedatives have to be used in debridement therapy?
As the maggots may eat the nerve endings.
155
What is the maximum time that maggots can stay in indolent wounds for in debridement therapy before they turn into flies?
2 days.
156
Do you use the green or the blue blowfly in debridement therapy?
Green - Lucillia sericata.
157
Other than debridement therapy, what else can be used to treat indolent wounds?
Manuka honey/ honey therapy.
158
Honey therapy is suitable treatment for wound infections, ear infections, urinary infections and dysentery but not for more serious infections such as septicaemia, pneumonia and meningitis. True or false?
False. Manuka honey can treat a wide range of infections including more serious ones.
159
Manuka honey is sold is graded with a UMF (Unique Manuka Factor.) What factors of honey would you use on wounds?
20 and 25.
160
What four properties of Manuka honey allow it to be used in the treatment of many different infections due to their contribution to its antibacterial properties.?
1. Osmotic effect
2. pH
3. Hydrogen peroxide
4. Non peroxide antibiotic activity.
161
What property associated with the antibiotic ability of Manuka honey is being described here?
Honey has a low water activity as most water within the honey is associated with constituent monosaccharides.
Osmotic effect.
162
What property associated with the antibiotic ability of Manuka honey is being described here?
Glucose oxidase is present in the honey which releases _____. This compound can act as an antiseptic.
Hydrogen peroxide activity.
163
What property associated with the antibiotic ability of Manuka honey is being described here?
This property prevents the bacteria from being able to grow as it is too low.
pH (which is normally between 3.2 and 4.5).
164
What property associated with the antibiotic ability of Manuka honey is being described here?
This is attributed to a variety of complex organics including polyphenols, methylglyoxals and various other unidentified compounds.
Non-peroxide antibiotic activity.
165
Apart from indolent would, what specific wound can Manuka honey help heal?
Mastectomy wounds.
166
What is mycotherpy?
Use of living mycelium of an antibiotic producing fungus on a wound.
167
Fungi producing what chemicals can be used in mycotherapy?
Antibiotic chemicals. These include penicillin, patulin and more complex chemicals.
168
Why can mould filtrate no longer be used in mycotherapy?
As the bacteria are too resistant to antibiotics.
169
How can mycelium bind the wound together in mycotherapy?
It can absorb blood and puss.
170
What did Cecil George Pain do?
He was the first person to achieve documented cures with penicillin.
171
What is Alfred Russel Wallace usually co-credited in discovering?
Natural selection.
172
Who are William Charles Wells and Patrick Matthew ?
They are pre Darwin originators of natural selection.
| Patrick Matthew was half American.
173
John Tyndall, Henry Huxley and Alfred Wallace all accepted what?
They were all Victorian scientists that accepted that Darwin was beaten in the discovery of natural selection.
174
What studies the evolutionary history of microorganisms?
Phylogeny.
175
Phylogeny uses DNA sequences called what?
Molecular clocks. These look at conserved proteins and how these undergo random and steady change.
176
What is a cladogram?
A phylogenetic tree.
177
Is the phylogentic tree of life bases on the comparative analysis of mRNA, rRNA or tRNA sequence?
rRNA.
178
What is taxonomy?
The discipline that deals with the classification of organisms.
179
Morphology, differential staining, studying metabolic properties, phage typing, fatty acid profiling and mass spec are examples of what type of analysis?
Phenotypic analysis.
180
All methods of phenotypic analysis require pure samples. True or false?
False. Looking at morphology and using differential staining do not, however all the other methods do.
181
DNA hybridisaton, FISH, rDNA 16s sequencing, multi locus sequence typing and whole genome sequencing are an example of what type of analysis?
Genotypic analysis.
182
If two organisms have between 25%-75% DNA hybridiasation, are they are not in the same species. What are they in the same?
Genus. Less than 25% would make them be in a different genere.
183
What three processes in bacteria generate diversity?
1. Binary fission.
2. Haploidy.
3. Genetic fluidity.
184
What type of specimen do you need for transmission electron microscopy?
A thin section.
185
What are the main three differences between a prokaryote and eukaryote cell?
1. Size
2. Presence/absence of a nucleus
3. Compartmentalization
186
What is DNA complexed with in the nucleus?
Histones.
187
The nucleus is the site of all cellular RNA. True or false?
False. Although rRNA is synthesized there it is found in the nucleus.
188
What organelle allows for toxins to be broken down?
The SER.
189
What organelle contributes to synthesis of lipids and steroids?
SER.
190
What organelle allows for carbohydrate synthesis?
Golgi complex.
191
Peroxisomes and lysosomes both originate from the Golgi. True or false?
False. Peroxisomes originate from the ER.
192
What is the main role of a peroxisome?
Lipid metabolism via the oxidation of alcohols and fatty acids.
193
Do mitochondria and chlorplasts multiply by division?
Yes.
194
Do chloroplasts and the mitochondria have its own transcription and translation machinery?
No. It has its own translation machinery but not transcription.
195
Chloroplasts are made from _____ forming _____ found in the _____.
Thylakoids, grana, stroma.
196
What molecule connects adjacent mirotubules?
Dynein.
197
Motion in the microtubules is carried out by what process?
ATP hydrolysis from the dynein.
198
When microtubules slide against each other what movement occurs?
A whiplike movement.
199
What is a nucloid made up off (usually)?
A single circular ds chromosome.
200
Prokaryotes contain no organelles. True or false?
False. Some do. This includes magnetosomes, photosynthetic membranes and few internal membranes.
201
What three inclusion bodies can be found in prokaryotes?
1. Carboxysomes
2. Storgage granules
3. Gas vesicles
202
What type of cell contains a nuceloid?
Prokaryote.
203
What can be covalently bound to the peptidoglycan in the cell membrane?
Polymers.
204
What is a pilus?
An appendage found in prokaryotic cells dedidicated to conjuction.
205
What is a fimbriae/ pili?
An appendage found in prokaroytic cells that is involved in the adherance to host cell/surfaces. They are antigenic structure made of one major protein.
206
What is the appendage founf in prokaryotes is a supramolecular assembly involved in bacterial motility?
Flagella.
207
What size ribosomes are found in eukaroytes?
80s.
208
What size ribosomes are found in prokaryotes?
70s.
209
What size ribosomes are found in chloroplasts and mitrochondria?
70s.
210
What type of cell has a plasma membrane containing carbohydrates and sterols?
Eukaryotes.
211
Do chloroplasts and mitochondria divide by mitosis or binary fission?
Binary fission.
212
How many subunits are found in prokaryotic flagella?
2.
213
What type of cell has the more complex envelope?
Prokaryotic.
214
How many circular DNA molecules are usually found in prokaryotes?
1.
215
Mitochondria originated from the engulfment of an H2 producing _____ by an H2 producing consuming _____.
Bacterium, archae.
216
Did chloroplasts or mitochondria originate in the cell first?
Mitochondria.
217
What type of parasites are viruses?
Obligatory.
218
Can viruses infect all living organisms, including other viruses?
Yes.
219
What is the size of a normal virus?
2-20kb.
220
Apart from being an isocahedral shape, what shapes are often found in viruses?
Helical symmetry.
221
The envelope of a virus always contains glycolipids taken from a host. True or false?
False. They can be virually encoded.
222
What structures does a bacteriophage contain?
Icosahedral and filamentous structures.
223
What is smallpox (viridae) virus an example off (structurally) ?
A non symmetrical virus.
224
What classes of virus contain DNA?
1,2,7.
225
What classes of virus contain RNA?
3,4,5,6.
226
What virus class contains the Papillomavirus which can cause cervical cancer and warts?
1.
227
What virus class contains the Adeno-associated virus?
2.
228
What virus class contains the reovirus?
3.
229
What virus class contains foot and mouth disease, pollio and HepA/C?
4.
230
What class of virus contains the influenza virus?
5.
231
What virus class contains the HIV virus?
6.
232
What virus class contains dsDNA ?
1.
233
What virus class contains ssDNA ?
2.
234
What virus class contains dsRNA?
3.
235
What virus class contains (+)ssRNA
4.
236
What virus class contains (-)ssRNA?
5.
237
What virus class contains reverse RNA?
6.
238
What virus class contains reverse DNA?
7.
239
What are the main two type of viruses?
1. Bacteriophages
| 2. Animal and plant viruses.
240
What morphology does Staphylococcus aures/ pneumoniae have?
Cocci.
241
What morphology does E.coli have?
Rod.
242
What are the five possible morphologies of a bacterial cell?
1. Cocci
2. Rods
3. Curved
4. Spiral
5. Exotic.
243
What feature of a bacteria allows an efficient exchange and growth rate and for rapid evolution due to high selection rate of mutation?
The large surface area to volume ratio.
244
Bacteria can produce pigments. What does this result in?
The cell having colour.
245
What causes the odour in some bacteria?
Their metabolism.
246
What two metabolic process in bacteria can cause smell?
1. Degradation of apocrine secretion products.
| 2. Decarboxylation of amino acids to produce polyamines.
247
What is crystal violet used for?
As a stain to stain bacteria.
248
What is safranin used for?
As a counterstain to stain bacteria.
249
What is used to fix the stain in the staining process of bacteria?
Iodine.
250
Do gram positive bacteria have a outer membrane?
No.
251
What type of cell walls do gram positive bacteria have?
Thick.
252
What type of cell wall do gram negative bacteria have
Thin.
253
Do gram negative bacteria have an outer membrane?
Yes.
254
Where are capsules in a bacterial cell found?
Bound to the outermembrane.
255
Most capsules are made of polysaccharides. What else can they be made of?
Amino acids.
256
What part of the bacterial cell confers resistance to host phagocytes/bacteriophages and keep the environment hydrated?
Capsules.
257
Exopolysaccharides can be homo or heteropolysaccharides. How are they attached to the cell surface?
Non covalently.
258
What part of the bacteria is important in the formation of biofilms and can have economical imporantce, such as xanthan gum?
Exopolysaccharides.
259
Do S layers exist in most model organisms?
No they are faculative structures.
260
How are S layers attached to the bacterial cell?
Non covalently.
261
What part of the bacterial cell helps give the cell shape via the cytoskeleton?
Peptidoglycan. It also acts as a scaffold to display polymers and proteins.
262
What are the 3 main components of the cytoplasmic membrane in bacterial cells?
1. Phospholipids
2. Hopanoids
3. Proteins
263
What is the role of hopanoids in bacterial cell membranes?
Modulates the fluidity of the membrane and permeability.
264
Bacterial chromosomes are always made of dsDNA. true or false?
True.
265
Is the term photo, chemo, organo litho used when preformed molecules are used as an energy source?
Chemo.
266
Is the term photo, chemo, organo litho used when inorganic molecules are used as an electron source?
Litho.
267
What is the name given to a molecule that uses organic compounds as a carbon sourced?
Heterotroph.
268
What is the name given to a molecule that uses inorganic compounds as a carbon sourced?
Autotroph.
269
What are the major phyla which consist of archae?
1. Euryarcheota
| 2. Crenarcheaota
270
Do archae have an S layer?
Yes.
271
What is the S layer composed of in archae?
Glycoprotein.
272
Archae always have a cell wall. true or false?
False.
273
What is the cell wall made out of in archae?
Pseudomurein- a heteropolymer.
274
What two things are the cell walls in archae resistant to?
1. lysozymes
| 2. Most antibiotic targeting proteins.
275
What common membrane component is found non in archae membranes?
Fatty acids.
276
Archae membranes do not contain fatty acids. what do they contain instead?
Isoprenes.
277
The cell membranes in archae do not contain ester linkages. What linkages do they contain?
Ether.
278
Are archae or bacterial cell membranes more stable?
Archea.
279
Archae membranes are made of only monolayers. true or false?
False. they can also be made of bilayers or a mixture of both.
280
Like bacteria archae have circular chromosomes and plasmids. They also contain histones and multiple replication origins. True or false?
True.
281
What two polymerases can archae encode? which one is specific to archae?
B and D. D is specific to archae. Eukarya encode B and bacteria encode C.
282
Do archae contain introns?
Yes.
283
Do archase use translation factors?
Yes.
284
Is transcription and translation coupled in archae?
Yes.
285
What ribsomes are present in archae?
70s.
286
Hyperthermophiles grow in 80-120 degrees. They are often acidophiles and require what element for growth?
Sulphur.
287
What salt concentration do halophiles require?
Up to 5M of NaCl.
288
What sort of environments are methagons found in?
Anerobic.
289
What can methogens use as an electron acceptor?
Acetate/formiate and CO2.
