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Microbiology 323 > Exam 1 Material > Flashcards

Exam 1 Material Flashcards

1
Q

How are bacteria and archaea different from eukaryotes?

A

1) the way their DNA is packaged; bacteria lack nucleus and histones
2) the makeup of their cell wall; most bacteria have peptidoglycan and archaea have pseudomurein
3) their internal structures; archaea and most bacteria lack of membrane-bound organelles

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2
Q

What structures are found in all bacteria?

A

cell membrane, chromosomes, ribosomes, cytoplasm

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3
Q

What structures are found in some, but not all bacteria?

A

cytoskeleton, pilus, glycocalyx, inclusion/granule, microcompartments, plasmid, flagellum

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4
Q

cell membrane

A

thin sheet of lipid and protein that surrounds the cytoplasm and controls the flow of materials in and out of the cell

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5
Q

bacterial chromosome

A

composed of condensed DNA molecules; dna directs all genetics and heredity of the cell

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6
Q

ribosomes

A

tiny particles composed of protein and RNA that are the sites of protein synthesis

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7
Q

cytoplasm

A

water-based solution filling the entire cell

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8
Q

cytoskeleton

A

long fibers that encircle the cell just inside the cytoplasmic membrane and contribute to the shape of the cell

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9
Q

pilus

A

appendage used for drawing another bacterium close in order to transfer dna

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10
Q

What appendage is used to transfer DNA from one bacterium to another?

A

Pilus

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11
Q

glycocalyx

A

coating or layer of molecules external to the cell wall serves protective, adhesive, and receptor functions

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12
Q

inclusion/granule

A

stored nutrients deposited into dense crystals

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13
Q

microcompartments

A

protein-coated packets used to localize enzymes and other proteins in the cytoplasm

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14
Q

plasmid

A

double-stranded DNA containing extra genes

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15
Q

flagellum

A

specialized appendage, movement pushes the cell foreward and provides motility

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16
Q

What is the average size of bacteria?

A

1 micrometer

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17
Q

What is the circumference of cocci?

A

1 micrometer

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18
Q

What is the average length and width of rods?

A

Length:2 micrometers; width: 1 micrometer

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19
Q

mycoplasma pneumoniae

A

respiratory infections

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20
Q

spirilla

A

a rigid, helix, twisted twice or more along its axis like a corkscrew

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21
Q

spirochetes

A

a spiral cell that contains periplasmic flagella

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22
Q

How can cocci bacteria be arranged?

A

single, diplococci, tetrads, staphlococci/micrococci, streptococci or sarcina

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23
Q

diplococci

A

pairs of cocci

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24
Q

tetrads

A

groups of four

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25
Q

staphlococci

A

irregular clusters

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26
Q

streptococci

A

chains

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27
Q

sarcina

A

cubical packet of eight, sixteen, or more cells

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28
Q

What are the arrangements of bacillus bacteria?

A

single, diplobacilli, streptobacilli, palisades

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29
Q

palisades

A

cells of a chain remain partially attached by a small hinge region at the ends

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30
Q

What is an example of a structure possessed by some but not all prokaryotes?

A

Flagella

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31
Q

What appendages are used for motility?

A

Flagella and axial filaments(spirochetes)

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32
Q

What appendages are used for attachment/adhesion?

A

Fimbrae, pili, and nanotubes/nanowires

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33
Q

monotrichous

A

one flagella at one end of cell

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34
Q

peritrichous

A

multiple flagella all covering random sites on the cell

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35
Q

amphitrichous

A

multiple flagella at both ends of cell

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36
Q

lophotrichous

A

multiple flagella at one end of cell

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37
Q

chemotaxis

A

movement of bacteria in response to chemical signals

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38
Q

positive chemotaxis

A

movement toward favorable chemical stimulus

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39
Q

negative chemotaxis

A

movement away from a repellant

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40
Q

Which chemotaxis moves towards favorable stimulus?

A

positive chemotaxis

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41
Q

Which chemotaxis moves away from a repellant?

A

negative chemotaxis

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42
Q

Run

A

rotation of flagellum counterclockwise, resulting in smooth linear direction

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43
Q

Tumble

A

reversal of the direction of the flagellum, causing the cell to stop and change course

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44
Q

Spirochetes

A

possess an unusual, wriggly mode of locomotion due to periplasmic flagella

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45
Q

borelia burgdorferi

A

primary causative agent of lyme disease

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46
Q

treponema pallidum

A

causative agent of syphilis

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47
Q

Fimbria/fimbrae

A

small, bristle-like fibers sprouting off the surface of many bacterial cells

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48
Q

What do fimbrae aid in?

A

Allow tight adhesion between fimbrae and epithelial cells, allowing bacteria to colonize and infect host tissues

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49
Q

Pilus

A

used in conjugation between bacterial cells

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50
Q

What appendage is highly characterized in gram-negative bacteria?

A

Pilus

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51
Q

What do type IV pilus do?

A

Type IV pilus can transfer genetic material, act like fimbrae & assist in attachment

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52
Q

Nanotubes

A

very thin, long, tubular extensions of the cytoplasmic membrane

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53
Q

What purpose do nanotubes serve?

A

Used as channels to transfer amino acids or to harvest energy
Communicate with other bacteria and archaea

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54
Q

S layer

A

single layers of thousands of copies of a single protein linked together

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55
Q

When is the s layer produced?

A

When bacteria are in a hostile environment

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56
Q

Glycocalyx

A

coating of repeating polysaccharide or glycoprotein unitsi

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57
Q

Slime layer

A

loose, protects against loss of water and nutrients

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58
Q

Capsule

A

more tightly bound, denser, thicker

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59
Q

What does the capsule protect against?

A

protects against phagocytosis by white blood cells

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60
Q

Biofilm

A

responsible for persistent colonization of plastic catheters, IUDS, metal pacemakers, and other implanted medical devices

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61
Q

What is an example of biofilm?

A

plaque on teeth protects bacteria from becoming dislodged

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62
Q

Cell envelope

A

composed of 2 or 3 layers that each perform a distinct function, but together act as a single protective unit

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63
Q

What parts make up the cell envelope?

A

outer membrane, cell wall, and cytoplasmic membrane

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64
Q

Cytoplasmic membrane

A

a phospholipid bilayer with embedded proteins

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65
Q

What occurs at the cytoplasmic membrane?

A

energy reactions, nutrient processing, synthesis

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66
Q

What is the purpose of the cytoplasmic membrane?

A

regulates transport of nutrients and wastes

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67
Q

Selectively permeable

A

special carrier mechanisms for passage of most molecules

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68
Q

Cell wall

A

helps determine the shape of bacterium, provides structural support to keep bacterium from bursting when undergoing change in osmotic pressure

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69
Q

How do drugs work at treating infections?

A

drugs target cell wall, disrupting its integrity and causing cell lysis

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70
Q

Cell lysis

A

disintegration or rupture of cell

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71
Q

Peptidoglycan

A

helps cell wall gain relative rigidity

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72
Q

What is the peptidoglycan layer composed of?

A

compound composed of a repeating framework of long glycan(sugar) chains cross-linked by short peptide (protein) fragments

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73
Q

Gram-positive cell wall

A

thick, homogeneous sheet of peptidoglycan
20 to 80 mm in thickness

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74
Q

What acids is the gram-positive cell wall composed of?

A

teichoic acid and lipoteichoic acid

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75
Q

What function do teichoic acid and lipoteichoic acid have?

A

cell wall maintenance and enlargement during cell divison

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76
Q

Gram-negative cell wall

A

single, thin sheet of peptidoglycan

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77
Q

What does the thinness of the gram-negative cell wall cause?

A

greater flexibility and sensitivity to lysis

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78
Q

What is the difference between gram-negative outer membrane and other membranes?

A

gram-negative cell membrane contains specialized polysaccharides and proteins

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79
Q

What types of molecules pass through the outer membrane of gram-negative cell wall?

A

Small molecules i.e. glucose and monosaccharides

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80
Q

Porin proteins

A

special water-filled channels that only allow certain small molecules to penetrate, water soluble compounds
not found in cytoplasmic membrane

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81
Q

lipoproteins

A

connects outer membrane to peptidoglycan layer

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82
Q

lipopolysaccharides

A

stabilizes the outer membrane, contributes to the negative charge of outer membrane

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83
Q

What function do lipopolysaccharides have in bacteria?

A

acts as permeability barrier, helps protect bacteria from host defense

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84
Q

What does the O-antigen of lipopolysaccharides do?

A

signaling and as a receptor; elicits an immune response by infected host

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85
Q

endotoxin

A

lipid a portion; stimulates fever and shock reaction in gram-negative infections

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86
Q

What are examples of gram-negative infections that could induce endotoxins?

A

Meningitis and typhoid fever

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87
Q

What happens if LPS or lipid a enters the bloodstream?

A

A form of shock develops for which there is no direct treatment

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88
Q

What does the extra barrier in gram-negative bacteria do?

A

it is resistant to certain microbial chemicals and is more difficult to inhibit or kill than gram-positive bacteria

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89
Q

How do alcohol-based compounds affect cells?

A

alcohol-based compounds dissolve lipids in the outer membrane and therefore damage the cell

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90
Q

What is an example of alcohol-based compounds being used?

A

alcohol swabs used to clean the skin before certain medical procedures

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91
Q

What is the difference in treatment between gram-positive infections and gram-negative infections?

A

Gram-negative infections require drugs that can cross the outer membrane

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92
Q

What are the steps in a gram stain?

A

1) crystal violet; CV is added to cells in smear and changes/stains cells purple
2) gram’s iodine

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93
Q

What are the steps in a gram stain?

A

1) crystal violet; CV is added to cells in smear and changes/stains cells purple
2) gram’s iodine; stabilizer causes the dye to form large complexes in the peptidoglycan layer. thicker gram-positive cell walls are more firmly able to trap large complexes
3) alcohol; alcohol dissolves lipids in outer membrane. removes dye from peptidoglycan layer in gram-negative cells
4) safranin; gram-neg bacteria become present due to colorlessness

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94
Q

examples of mycrobacterium

A

tuberculosis and leprosy

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95
Q

What is a key feature of mycobacterium and norcardia when gram stained?

A

Stain gram-positive, but bulk of cell wall is comprised of unique lipids

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96
Q

mycolic acid

A

fatty chains found in cell walls of acid-fast bacteria; contributes to pathogenecity of bacteria
*makes bacteria highly resistant to certain chemicals and dyes

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97
Q

What is different about the cell walls of archaea?

A

some cell walls are composed of entirely polysaccharides while others have cell walls made of pure protein

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98
Q

Do archaea contain peptidoglycan?

A

archaea lack true peptidoglycan structure, some may not have cell wall

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99
Q

Mycoplasmas

A

naturally lack a cell wall

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100
Q

Why are mycoplasmas resistant to certain antibiotics?

A

due to lack of cell wall, naturally resistant to antibiotics that target the cell wall

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101
Q

hopanoids

A

cholesterol analog in cell membrane that stabilize the cell against lysis

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102
Q

L forms

A

some naturally have a cell wall but lose it during part of their life cycle; plays a role in persistent infections; resistant to antibiotics

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103
Q

cytoplasm

A

70 to 80% water, complex mixture of sugars, amino acids, and salts

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104
Q

What is the purpose of the cytoplasm?

A

serves as a pool for building blocks for cell synthesis or sources of energy

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105
Q

Where is the heredity material of bacteria stored?

A

bacterial chromosomes

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106
Q

Where is DNA aggregated?

A

nucleoid

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107
Q

plamids

A

nonessential pieces of DNA

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108
Q

What do plasmids confer?

A

protective traits such as drug resistance and toxins and enzyme production

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109
Q

ribosomes

A

site of protein synthesis

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110
Q

What are ribosomes composed of?

A

rRNA and protein

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111
Q

How are ribosomes measured?

A

using the Svedberg unit, which corresponds to the rate of sedimentation when centrifuged

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112
Q

What is the small subunits measurement?

A

30S

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113
Q

What is the large subunits measurement?

A

50S

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114
Q

What is the large and small subunits measurement together?

A

70S

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115
Q

What is the measurement of an archaeal ribosome?

A

70S

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116
Q

What is the measurement of a eukaryotic ribosome?

A

80S

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117
Q

What are inclusion bodies used for?

A

food storage; pack gas into vesicles for buoyancy; store crystals of iron oxide with magnetic properties

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118
Q

bacterial microcompartments

A

outer shells made of protein, arranged geometrically

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119
Q

What do microcompartments contain?

A

concentrates CO2 and houses RubisCO
packed full of enzymes designed to work together in biochemical pathways

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120
Q

cytoskeleton

A

arranged in helical ribbons around the cell beneath cell membrane
contribute to cell shape

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121
Q

What is special about the cytoskeleton in noneukaryotic cells?

A

may be a potential target for antibiotic development

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122
Q

action homologue

A

MreB: many rods, helps determine cell shape?

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123
Q

Tubulin homologue:Fts2 protein

A

forms a ring that constricts during cell divison

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124
Q

bacterial endospores

A

dormant bodies

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125
Q

Where are the medically important species found in endospores?

A

genera Bacillus and Clostridia

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126
Q

vegetative cell

A

metabolically active

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127
Q

sporulation

A

induced by depletion of nutrients in the environment

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128
Q

What is special about endospores?

A

resist extremes of heat, drying, freezing, radiation, and chemicals that would kill vegetative cells

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129
Q

bacillus anthracis

A

agent of anthrax

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130
Q

clostridium tetani

A

cause of tetanus

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131
Q

clostridium perfringes

A

cause of gas gangrene

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132
Q

clostridium botulinum

A

cause of botulism

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133
Q

clostridium difficile

A

“c. diff” a serious gastrointestinal disease

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134
Q

What domain is archaea more closely related to?

A

Eukarya; lack peptidoglycan

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135
Q

Why is archaea more closely related to eukarya than bacteria?

A

lack peptidoglycan; histone proteins; protein synthesis and ribosomal subunit structures are similar; share rRNA sequences not found in bacteria

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136
Q

extremophiles

A

some live at extremely high or low temperatures, some need extremely high salt or acid concentrations to survive, some live on sulfur, some produce methane

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137
Q

Bergey’s manual of Systemic Bacteriology

A

a comprehensive view of bacterial and archael relatedness; based on rRNA sequencing

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138
Q

Bergey’s manual of Determinative Bacteriology

A

based entirely on phenotypic characteristics; categorizes organisms based on traits commonly assessed in clinical, teaching, and research labs such as seen on in a microscope or metabolic capabilities

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139
Q

bacterial species

A

a collection of bacterial cells, all of which share an overall similar pattern of traits; should share at least 70 to 80% of their genes

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140
Q

subspecies/strain/type

A

bacteria of same species that have differing characteristics

141
Q

serotype

A

representatives of a species that stimulate a distinct pattern of antibody responses because of a unique surface molecules

142
Q

When did the first eukaryotic cells appear?

A

about 2.5 billion years ago

143
Q

What did bacteria, archaea, and eukarya all evolve from?

A

the Last Common Ancestor

144
Q

What was true about the first primitive eukaryotes?

A

they were likely single celled and independent

145
Q

What happened to cells over time?

A

began aggregating and forming colonies

146
Q

What do the cells in colonies do?

A

the cells in colonies became specialized to perform a specific function

147
Q

What happened to complex multicellular organisms?

A

they lost the ability to survive seperately from the intact colony about 1.5 billion years ago

148
Q

What genus is always unicellular?

A

protozoa

149
Q

What genus are either unicellular or multicellular?

A

fungi and algae

150
Q

What genus are always multicellular?

A

nelminths(have unicellular egg)

151
Q

How many species of protozoa are there?

A

12,000 single-celled creatures

152
Q

What do protozoa do?

A

most are harmless, free-living inhabitants of water and soil
important predators of bacteria

153
Q

How often do protozoa cause infections in humans?

A

few species are pathogens responsible for hundreds of millions of infections each year

154
Q

What are protozoans made up of?

A

single cells containing all of the major eukaryotic organelles except chloroplasts

155
Q

What two parts does the cytoplasm of protozoa divide into?

A

ectoplasm and endoplasm

156
Q

ectoplasm

A

clear outer layer involved in locomotion, feeding, and protection

157
Q

endoplasm

A

granular inner region housing the nucleus, mitochondria, and food and contractile vacuoles

158
Q

contractile vacuoles

A

common in protists; contractile vacuoles help maintain osmoregulation

159
Q

steps of osmoregulation

A

1) water enters due to osmosis
2) excess water enters contractile vacuole
3) contractile vacuole swells
4) contractile vacuole moves to edge of cell
5) contractile vacuole bursts and expels water
6) cycle is repeated

160
Q

phagocytic vacuoles

A

allow some protists to ingest food
engulfment
digestion of prey in food vacuole

161
Q

How do protozoan move?

A

move via pseudopods, cilia, or flagella

162
Q

What does the cell membrane of protozoan do?

A

regulates food, wastes, and secretions

163
Q

ciliates cell shape

A

remain constant

164
Q

amoebas cell shape

A

changes constantly

165
Q

What is the size of protozoans?

A

range from 3 to 300 micrometers

166
Q

How do protozoan eat?

A

some have special feeding structures, some absorb food directly through the cell membrane

167
Q

How do pathogenic species eat?

A

some may live on fluids of their host or actively feed on tissues

168
Q

What are the predominant habitats of protozoa?

A

fresh and marine water, soil, plants, and animals

169
Q

trophozoite

A

motile feeding stage requiring ample food and moisture to stay alive

170
Q

cyst

A

dormant, resting stage, when conditions in the environment become unfavorable

171
Q

What are cysts resistant to?

A

heat, drying and chemicals

172
Q

How can cysts be dispersed?

A

by air currents; important factor in the spread of disease

173
Q

What is the life cycle of protozoa?

A

1) trophozoite active feeding stage
2) cells round up, loses motility
3)mature cyst dormant resting stage
4)cyst wall breaks open
5)trophozoite is reactivated

174
Q

What phases do some protozoan groups exist in?

A

Trophozoite phase

175
Q

What stages do many protozoa alternate between?

A

trophozoite and cyst stage depending on habitat

176
Q

trichomonas vaginalis

A

common STD, does not form cysts and must be transmitted by intimate contact

177
Q

entamoeba histolytica/giardia lambia

A

form cysts and are readily transmitted by contaminated water and foods

178
Q

How do protozoa reproduce?

A

all protozoa reproduce by simple, asexual mitotic cell division

179
Q

How do the ciliates participate in conjugation?

A

two cells fuse and exchange micronuclei

180
Q

What are some benefits of fungi?

A

play an essential role in decomposing organic matter and returning minerals to soil
able to breakdown complex carbon complexes
form stable associations with plant roots and increase their ability to absorb water and nutrients

181
Q

What role do fungi play in healthcare?

A

engineered to produce large quantities of antibiotics, alcohol, organic acids and vitamins

182
Q

hyphae

A

long, threadlike cells found in bodies of filamentous fungi

183
Q

yeasts

A

round to oval shape, asexual reproduction, budding

184
Q

pseudohypha

A

chains of yeast cells

185
Q

What are yeasts?

A

wild saprotrophic, domesticated, or pathogenic species

186
Q

How many species of yeast are there?

A

1500 species

187
Q

Where are yeast found?

A

wild saprotrophic species in soils, on plant surfaces, sugary mediums(nectar, fruits)

188
Q

What are domesticated species of yeast used for?

A

used to make breads, beer, wine, chocolate

189
Q

What is the morphology of fungi?

A

cells of most microscopic fungi grow in loose associations of colonies

190
Q

What do colonies of yeast look like?

A

much like bacteria; they have a soft, uniform texture and appearance

191
Q

mycelium

A

the woven, intertwining mass of hyphae that makes up the body or colony of mold

192
Q

septa

A

segments or cross walls found in most fungi that allow the flow of organelles and nutrients between adjacent environments

193
Q

What do nonseptate hyphae look like?

A

one, long, continuous cell

194
Q

absorptive nutrition

A

secretion of nutrients, extracellular digestion, absorption of solubilized small compounds, apical growth of hyphae

195
Q

heterotrophic

A

acquire nutrients from a wide variety of organic substrates

196
Q

saprobic

A

obtain nutrients from the remnants of dead plants and animals in soil or aquatic habitats

197
Q

What conditions do fungi typically thrive in?

A

nutritionally poor or adverse environments, and those with high salt or sugar content

198
Q

parasitic

A

organism that lives in or on another organism for the purpose of acquiring nutrients

199
Q

Where do parasites grow?

A

on the bodies of living animals or plants causing harm

200
Q

pathogens

A

cause disease in host

201
Q

mutualistic

A

rely on partner organism for complex carbohydrates
rely on photosynthetic host for fixed carbon

202
Q

spores

A

primary reproductive mode of fungi
can be dispersed through the environment by air, water, and living things

203
Q

What are spores resistant to?

A

resistant to drying, heating, freezing, and chemicals

204
Q

What are the two types of asexual mold spores?

A

sporangiospores and condidospores

205
Q

How are sporangiospores formed?

A

formed by successive cleavages within a saclike head called sporangium, which is attached to a stalk, the sporangiospore

206
Q

condidiospores

A

free spores not enclosed by a spore-bearing sac

207
Q

How do condidiospores develop?

A

by successive mitotic divisons, the pinching off of the tip of a special fertile hypha or by the segmentation of a pre-existing vegetative hypha

208
Q

aspergillus flavus

A

green conidia and produces a flatoxin, the most toxigenic cancer-causing compound found in nature

209
Q

How many species of fungi can cause human disease?

A

about 300 species

210
Q

How do spores affect AIDS patients?

A

harmless spores can cause opportunistic infections in AIDS patients

211
Q

How do fungi affect allergies?

A

fungal cell walls give off substances that cause allergies

212
Q

How do poisonous mushrooms affect human health?

A

toxins produced by poisonous mushrooms can induce neurological disturbances and death

213
Q

What does aspergillus flavus produce?

A

produces a potentially lethal poison called aflatoxin to animals who eat contaminated grain

214
Q

Where does aflatoxin accumulate?

A

the liver

215
Q

How do fungi affect agriculture?

A

number of species are pathogenic to corn and grain
reduces crop production
can cause disease in domestic animals consuming contaminated feed crops
fungi rot fresh produce during shipping and storage

216
Q

What do photosynthetic eukaryotes do?

A

strict aerobes, use photosystems I and II for oxygenic photosynthesis

217
Q

chlorophyta

A

phototrophs have chlorophylls a & b, and carotenoid accessory pigments

218
Q

Where is chlorophyta food stored?

A

starch in purenoids

219
Q

What do chlorophyta cell walls have?

A

cellulose cell walls

220
Q

chlamydomona

A

large chloroplast, conspicious pyrenoid, osmoregulation controlled by two small contractile vacuoles at flagella base

221
Q

euglena

A

secondary endosymbiosis with green algae
commonly found in fresh water

222
Q

Are euglena pathogenic?

A

non-pathogenic

223
Q

How do euglena feed?

A

phagocytosis

224
Q

diatoms

A

chlorophylls a and c
accessory pigments
two-piece cell wall of silica
important in global carbon cycling
biofuels

225
Q

golden algae

A

chrysophytes
primarily unicellular marine and fresh water phototrophs
chlorophyll c
accessory pigment: fucoxanthin

226
Q

dinoflagellates

A

large group found in marine plankton cause toxic blooms in seawater
nutritionally complex
chlorophyll a and c, beta-carotene, xanthophylls unique

227
Q

chemoheterotrophs

A

absorb unique matter or engulf prey

228
Q

How do dinoflagellates get carbon and energy?

A

can be combination of autotroph and heterotrophic

229
Q

What occurs with Florida red tides?

A

red tide is normal October to November
increasing intensity
results in marine life death
100 manatees, dozen dolphins, 1000s of fish, 300 sea turtles

230
Q

essential nutrient

A

any substance that must be provided to an organism

231
Q

macronutrients

A

required in relatively large quantities and play principal roles in cell structure and metabolism

232
Q

What are some examples of macronutrients?

A

carbon, hydrogen and oxygen

233
Q

micronutrients

A

present in much smaller amounts and are involved in enzyme function and maintenance of protein structure

234
Q

What are some examples of micronutrients?

A

manganese, zinc, and nickel

235
Q

inorganic nutrients

A

an atom or simple molecule that contains a combination of atoms other than C and H

236
Q

Where are inorganic nutrients found?

A

found in earth’s crust, bodies of water, and the atmosphere

237
Q

What are some examples of inorganic nutrients??

A

metals and their salts(magnesium sulfate, ferric nitrate, sodium phosphate)
gases(oxygen, CO2) and water

238
Q

organic nutrients

A

contain carbon and hydrogen atoms and are usually the products of living things

239
Q

What are some examples of organic nutrients?

A

methane
large polymers(carbohydrates, lipids, proteins, and nucleic acids)

240
Q

What chemicals make up the cytoplasm?

A

water-70%
proteins
organic compounds: 97% of dry weight
elements CHONDS: 96% of dry weight

241
Q

heterotroph

A

an organism that must obtain its carbon in an organic form

242
Q

autotroph

A

an organism that uses inorganic CO2 as its carbon source

243
Q

What is unique about autotrophs?

A

has the capacity to convert CO2 to organic compounds
not nutritionally dependent on other living things

244
Q

phototroph

A

microbe that photosynthesizes

245
Q

chemotroph

A

microbe that gets its energy from chemical compounds

246
Q

photoautotroph

A

photosynthetic, produce organic molecules using CO2 that can be used by themselves and by heterotrophs

247
Q

photosynthetic

A

converts sun’s energy to chemical energy found in the bonds of organic molecules

248
Q

chemoautotroph

A

chemoorganic molecules, lithoautotrophs

249
Q

chemoorganic molecules

A

use organic compounds for energy and inorganic compounds as carbon source

250
Q

lithoautotroph

A

rely totally on inorganic minerals and require neither sunlight nor organic nutrients

251
Q

chemoheterotrophs

A

derive both carbon and energy from organic compounds
process those molecules through cellular respiration

252
Q

saprobes

A

free-living organisms that feed on organic detritus from dead microbes

253
Q

parasites

A

derive nutrients from the cells of tissues of a living host

254
Q

pathogens

A

cause damage to tissues or even death

255
Q

ectoparasites

A

live on the body

256
Q

endoparasites

A

live in the organs and tissues

257
Q

intracelluar parasites

A

live within cells

258
Q

obligate parasites

A

unable to grow outside of a living host

259
Q

What are examples of obligate parasites?

A

leprosy bacillus and syphillus spirochete

260
Q

What is an example of passive transport?

A

simple diffusion and facilitated diffusion

261
Q

simple diffusion

A

a fundamental property of atoms and molecules that exist in a state of random motion, require no energy

262
Q

facilitated diffusion

A

molecules bind to specific receptor in membrane and is carried to other side, molecule specific, goes both directions, rate of transport is limited

263
Q

What is an example of active transport?

A

carrier-mediated active transport

264
Q

carrier-mediated active transport

A

atoms or molecules are pumped in and out of cell by specialized receptors
driven by ATP or proton motive force

265
Q

active transport

A

transport of nutrients against the diffusion gradient or in the same direction as the natural gradient, but at a rate faster than by diffusion alone

266
Q

What substances would be transported actively?

A

monosaccharides, amino acids, organic acids, phosphates, and metal ions

267
Q

group translocation

A

chemically modifies molecule transported
energy-rich organic compound(not proton-motive force) drives transport

268
Q

phosphotransferase system

A

PTS
used widely in faculative or strict anaerobic bacteria

269
Q

What does the phosphotransferase system do?

A

transfer of phosphate, phosphorelay system
enzyme I and HPr are nonspecific cytoplasmic proteins

270
Q

What is enzyme II?

A

a protein complex, specific for different sugars

271
Q

What genus is PTS found in?

A

only found in bacteria

272
Q

ABC systems

A

200+ different systems identified in prokaryotes for organic and inorganic compounds

273
Q

ATP hydrolysis

A

provides energy and drives uptake of nutrients

274
Q

transporter

A

solute-binding protein attaches to transporter-releases solute

275
Q

iron transport by a siderophore and an ABC transport complex

A

minerals needed by the cell are often inaccessible in the environment outside the cell
iron is an important mineral nutrient, is mostly locked up in the inaccessible form:iron hydroxide

276
Q

Eurkaryotes endocytosis

A

eating and drinking by cells

277
Q

endocytosis

A

cell encloses the substance in its membrane
simultaneously forms a vacuole and engulfs the substance

278
Q

phagocytosis

A

accomplished by amoebas and white blood cells
ingest whole cells or large solid matter
in animals, fuse with lysosomes

279
Q

pinocytosis

A

ingestion of liquids such as oils or molecules in solution
fuses w endosomes

280
Q

zone of intolerance

A

extreme low temperatures and extremely high temperatures

281
Q

zone of physiological stress

A

slightly too cold, slightly too hot temperatures

282
Q

optimum range temperature

A

middle temperature

283
Q

extremophiles

A

harsh conditions, usually lethal

284
Q

What happens at the optimum temperature?

A

promotes the fastest rate of growth and metabolism

285
Q

psychophiles

A

optimum temperature below 15 celsius
capable of growth at 0 celsius
obligate w respect to cold and cannot grow above 20 celsius

286
Q

What would happen if you put psychophiles in refrigerator temperatures?

A

cause them to grow rather than inhibiting them

287
Q

What are the habitats of psychophilic bacteria, fungi, and algae?

A

lakes, rivers, snowfields, polar ice, and the deep ocean

288
Q

Are psychophiles pathogenic?

A

rarely pathogenic

289
Q

psychotrophs

A

grow slowly in the cold but have an optimum temperature between 15 and 30 celsius

290
Q

What are examples of bacteria that can grow at refrigerator temperatures?

A

staphylococcus aureus and listeria monocytogenes are able to grow at refrigerator temperatures and cause food-borne illness

291
Q

mesophiles

A

majority of medically significant microorganisms
grow at intermediate temperatures between 20 and 40 celsius

292
Q

What is the temperature range of human pathogens as mesophiles?

A

30 and 40 celsius

293
Q

thermoduric microbes

A

can survive short exposure to high temperatures but are normally mesophiles
common contaminants of heated or pasteurized foods

294
Q

What are examples of heat-resistant endospore formers?

A

bacillus and clostridium

295
Q

thermophiles

A

grow optimally at temperatures greater than 45 celsius

296
Q

Where do thermophiles live?

A

live on soil and water associated with volcanic activity, compost piles, and in habitats directly exposed to the sun

297
Q

What is the optimum temperature range for thermophiles?

A

45 to 80 celsius

298
Q

What temperature do extreme thermophiles live at?

A

80 and 121 celsius

299
Q

What gases influence microbial growth?

A

oxygen, and carbon dioxide

300
Q

Which gas has the most impact on microbial growth?

A

oxygen

301
Q

What three categories do microbes fall into regarding oxygen?

A

those that use oxygen and detoxify it
those than can neither use oxygen nor detoxify it
those that do not use oxygen but can detoxify it

302
Q

How do microbes process oxygen?

A

as oxygen enters cellular respiration, it is transformed into several toxic products

303
Q

singlet oxygen(O)

A

an extremely reactive molecule that can damage and destroy a cell by the oxidation of membrane lipids

304
Q

superoxide ion(O2-)

A

highly reactive

305
Q

hydrogen peroxide(H2O2)

A

toxic to cells and used as a disinfectant

306
Q

hydroxyl radical(OH-)

A

also highly reactive

307
Q

How do microbes protect themselves against damage from oxygen by-products?

A

most cells have developed enzymes that scavenge and neutralize reactive by-products

308
Q

aerobes

A

can use gaseous oxygen in their metabolism and possess the enzymes needed to process toxic oxygen products

309
Q

obligate aerobe

A

an organism that cannot grow without oxygen

310
Q

microaerophiles

A

are harmed by normal atmospheric concentrations of oxygen but require a small amount of it in metabolism

311
Q

facultative anaerobes

A

do not require oxygen for metabolism but use it when present

312
Q

anaerobes

A

lack the metabolic enzyme systems for using oxygen in respiration

313
Q

aerotolerant anaerobes

A

do not utilize oxygen but can survive and grow to a limited extent in its presence

314
Q

Are aerotolerant anaerobes harmed by oxygen?

A

not harmed by oxygen because they possess alternate mechanisms for breaking down peroxide and superoxide

315
Q

ph

A

defined as the degree of acidity or alkalinity of a solution

316
Q

How is ph measured?

A

by ph scale, a series of numbers ranging from 0 to 14

317
Q

What is the value of pure water?

A

7.0

318
Q

If the ph value decreases toward 0, what is it considered?

A

acidic

319
Q

If the ph value increases toward 14, what is it considered?

A

alkalinic

320
Q

neutrophiles

A

the majority of organisms live or grow in habitats between 6 and 8(7)

321
Q

acidophiles

A

organisms that thrive in acidic environments(0.5-~5.5)

322
Q

euglena mutabilis

A

grows in acid pools between 0 and 1

323
Q

thermoplasma

A

lives in coal piles at a ph of 1 or 2

324
Q

picrophilus

A

thrives at a ph of 0.7 but can grow at a ph of 0

325
Q

alkalinophiles

A

organisms that thrive in alkaline conditions(~8.5-12)

326
Q

natronomonas

A

live in hot pools and soils up to ph 12

327
Q

proteus

A

can create alkaline conditions to neutralize urine and colonize and infect the urinary system

328
Q

binary fission

A

process where one cell becomes two
parent cell enlarges
duplicates its chromosome
starts to pull its cell envelope together to the center of the cell

329
Q

steps in binary fission

A

1) a young cell
2) chromosome is replicated and new and old chromosomes move to different sides of the cell
3) protein band forms in the center of the cell
4)septum formation begins
5) when septum is complete, cells are considered divided. some detach, some remain attached

330
Q

growth on a plate

A

each individual colony is a result of 1000s of binary fission events

331
Q

generation time

A

the time required for a complete fission cycle, from parent cell to two daughter cells

332
Q

generation

A

increases the population by a factor of two

333
Q

What is needed for doubling to continue?

A

the environment remains favorable

334
Q

length of generation time

A

a measure of the growth rate of an organism

335
Q

What is the average generation time?

A

30 to 60 minutes

336
Q

What are some of the shortest generation times?

A

10 to 12 minutes

337
Q

What is the generation time of mycobacterium leprae?

A

10 to 30 days

338
Q

How long is the generation time of environmental bacteria?

A

measured in months

339
Q

How long is a pathogens generation time?

A

relatively short

340
Q

What is the equation that can be used to calculate the size of a population?

A

Nt=(N)2h
N is total number of cells in pop.
t denotes at some point in time
N represents starting number of cells
exponent denotes generation number
2n represents number of cells in generation

341
Q

growth curve

A

a predictable pattern of a bacterial population growth in a closed system can be measured

342
Q

lag phase

A

a “flat” period of growth due to newly innoculated cells require adjustment period
cells are not yet multiplying at max rate
population is sparse

343
Q

exponential growth phase

A

growth curve increases geometrically
will continue as long as cells have adequate nutrients and the environment is favorable

344
Q

stationary growth phase

A

cell birth & cell death rates are equal
cell division rate is slowing down
caused by depleted nutrients and oxygen, plus excretion of organic acids and biochemical pollutants

345
Q

death phase

A

cells begin to die at an exponential rate due to build up of wastes
speed of death depends on conditions
slower than exponential growth rate

346
Q

viable nonculturable state

A

many cells in a culture in the death phase stay alive but are dormant
will not grow on culture medium and are missed in colony counts

347
Q

What phase is more susceptible to antimicrobial agents and heat?

A

exponential growth phase

348
Q

What stage is more likely to spread infection?

A

individual in the early stages of infection

349
Q

turbidity

A

a clear nutrient solution becomes turbid, or cloudy, as microbes grow in it
greater turbidity=larger population size

Microbiology 323 (11 decks)

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