Bact Exam 1

Front 1

What are the two main ideas of bacteriology

Back 1

1. ubiquitousness - they are everywhere; live on us, cause disease, and can become pathogenic if in a sterile part of body
2. roles - they are trying to live on their own, and their life hurts us

Front 2

these two materials make up cell walls

Back 2

muramic acid
diaminopimelic acid

Front 3

bacteria have this type of ribosome

Back 3

70S

Front 4

Seven ways to differentiate different bacterial cells

Back 4

1. morphology
2. staining properties
3. motility
4. spore formation
5. oxygen requirement
6. carbon source utilization
7. biosynthetic products

Front 5

Three shapes of a bacterial cell

Back 5

1. coccus = sphere; diplococcus, streptococcus, staphylococcus
2. bacillus = rod
3. spiral or curve - helical coil like corkscrew

Front 6

3 surface morphologies

Back 6

rough - chalk, dry, powdery
smooth - like plastic, glistening, smooth
mucoid - wet, slimy, oozing, dripping

Front 7

2 types of cell borders

Back 7

regular, nice, neat
irregular, jagged, protruding, notches

Front 8

4 different morphologies of cell

Back 8

surface, border, height, pigment

Front 9

how to do a gram stain

Back 9

crystal violet - gram's iodine - alcohol (95% ethanol) - safarin red

Front 10

in a gram stain, which cell remains blue and which is turned to red?

Back 10

positive - blue
negative - red

Front 11

this part of the cell defines the cell, separating the inside from the outside

Back 11

cytoplasmic membrane

Front 12

these in the cytoplasmic membrane deal with electron transport, oxidative phosphorylation, wall synthesis, and complex lipid synthesis

Back 12

enzymes in cytoplasmic membrane

Front 13

this part of the cell gets small molecules from outside to inside

Back 13

cytoplasmic membrane

Front 14

this part of the cell deals with DNA replication

Back 14

cytoplasmic membrane

Front 15

this part of the cell plays a role in chemotaxis

Back 15

cytoplasmic membrane (flagellum anchored in cytoplasmic membrane)

Front 16

a convoluted invagination of the cell membrane

Back 16

mesosome

Front 17

two types of mesosomes

Back 17

sepal - near the septum
lateral - away from the septum

Front 18

this type of cell has an outer membrane

Back 18

gram negative

Front 19

the cell wall is located here, between the outer and cytoplasmic membranes

Back 19

periplasmic space

Front 20

two proteins in periplasmic space

Back 20

RNAse I - harmful
Binding proteins - transport

Front 21

two examples of spirillus cell shapes

Back 21

vibrio - shaped like a comma
spirochetes - helical

Front 22

ability of some bacteria to swim toward stimulus or away from stimulus

Back 22

chemotaxis

Front 23

names for the cell wall

Back 23

murein, sacculus, peptidoglycan

Front 24

all of these parts of the cell are covalently linked, forming one large molecule

Back 24

cell wall

Front 25

backbone of cell wall consists of these two sugars

Back 25

N-acetlyglucosamine
N-acetylmuramic acid

Front 26

S. Aureus tetrapeptide?

Back 26

L Ala D Gln L Lys D Ala

Front 27

two interesting points about tetrapeptides

Back 27

alternate DLDLDL
humans don't have D amino acides

Front 28

E. coli tetrapeptide?

Back 28

L Ala D Glu D/L Diaminopimelic acid D Ala

Front 29

what is always the last peptide in a tetrapeptide?

Back 29

D Ala, the other three may change but D Ala is always the same

Front 30

what is the bridging group for S. Aureus

Back 30

pentaglycine

Front 31

strength and rigidity of cell wall depends on this

Back 31

amount of crosslinkage

Front 32

cell wall synthesis occurs here

Back 32

inside cytoplasm, inside cytoplasmic membrane, outside the cytoplasmic membrane

Front 33

first molecule inside cytoplasm to start cell wall synthesis

Back 33

UDP - N - acetyl muramic Acid

Front 34

inside cytoplasm of cell wall synthesis, these three amino acids are addedd

Back 34

L Ala
D Glu
L Lys

Front 35

this enzyme converts L Ala to D Ala for cell wall synthesis

Back 35

rascemase enzyme

Front 36

molecule in cell wall synthesis after being inside cytoplasm and before in cytoplasmic membrane

Back 36

UDP -NAM Pentapeptide

Front 37

this lipid carrier moves UDP NAM pentapeptide into cytoplasmic membrane from cytoplasm in cell wall synthesis

Back 37

undecaprenyl phosphate

Front 38

after transferring molecule from cytoplasm to cytoplasmic membrane, this is left behind in cytoplasm

Back 38

UMP

Front 39

this molecule enters cytoplasmic membrane in cell wall synthesis

Back 39

carrier lipid - P - P - NAM - Pentapeptide

Front 40

two phosphates in carrier lipid - P - P - NAM - Pentapeptide form this bond

Back 40

pyrophosphate linkage

Front 41

during cell wall synthesis, in the membrane, while attached to carrier lipid, all cells will:

Back 41

add NAG to NAM
add bridging group to Lys (3rd AA)
(pentaglycine in staph aureus)

Front 42

during cell wall synthesis, in the membrane, while attached to carrier lipid, in staph aureus, this change takes place

Back 42

Glu -> Gln

Front 43

last step of cell wall synthesis in cytoplasmic membrane

Back 43

carrier PP stays inside (loses a phosphate)
Nam pentapeptide nag and bridging group go outside membrane

Front 44

2 steps that take place outside the membrane in cell wall synthesis

Back 44

transglycosylation
transpeptidation`

Front 45

this means you insert this subunit into a preexisting wall, which requires breaking bonds, insertion, and reforming bonds; process doubles cell wall every 20 minutes, which leads to elongation and cell division

Back 45

transglycocylation

Front 46

this means making new crosslinkages; bridging group connects to another subunit; 3rd AA L Lys connects to 4th D Ala

Back 46

transpeptidation

Front 47

during this reaction, 5th D Ala is released, forming a tetrapeptide

Back 47

transpeptidation

Front 48

difference in outer wall of gram positive and gram negative

Back 48

gram negative wall is 1 layer
gram positive wall is up to 40 layers, but with no outer membrane

Front 49

two roles of the cell wall

Back 49

structural rigidity - there are proteins in the cytoplasm analagous to eukaryotic cytoskeleton, which determines cell shape, which the wall then wraps around

protection
from physical force, lysis by internal osmotic pressure, keeps larger molecules out, keeps proteins in periplasmic space

Front 50

two specialized structures in gram positive bacteria

Back 50

ribitol techoic acid (Wall Teichoic acid) - extends from peptidoglycan to surrounding medium (short)
glycerol techoic acid (lipoteichoic acid, membrane teichoic acid) - anchored in cell membrane, extends through the 40 layers of peptidoglycan and into the medium (long)

Front 51

two specialized structures in gram negative bacteria

Back 51

lipopolysaccharides
lipoproteins

Front 52

3 parts of lipopolysaccharides

Back 52

lipid A (closest to cell), core, O side chain (outer most region)

Front 53

these four things make up the Lipid A

Back 53

2 glucosamine-phosphates
beta hydroxy myristic acid
other fatty acids - anchor the structure into the membrane

Front 54

lipid A is attached here

Back 54

to outer leaflet of outer membrane

Front 55

lipid A is this type of toxin

Back 55

endotoxin - means that the toxic molecule remains attached to the bacterial cell (bact usually exotoxins)

Front 56

symptoms/toxic properties of lipid A endotoxin

Back 56

fever, hyperglycemia, intravascular coagulation, hemorrhagic shock

Front 57

core of lipopolysaccharide made of this

Back 57

5 hexoses, 2 heptoses, and 3 molecules of KDO (ketodeoxyoctanoic acid)

Front 58

O side chain of lipopolysaccharide made of this

Back 58

up to 40 repeats of 3-5 saccharides which can vary in composition, making it antigenic

Front 59

o antigen useful for these purposes

Back 59

diagnostic purposes - typing sera - you prepare in adgance a defense against unknown organisms, and then test the o antigen against different antibodies until there is a reaction, can ID the organsim

Front 60

molecule which stimulates body to produce antibody

Back 60

antigen

Front 61

the response when antibodies are made to attack an antigen

Back 61

adaptive response

Front 62

specific to gram negative bact, its role is to anchor the outer membrane to peptidoglycan

Back 62

lipoprotein

Front 63

two parts of lipoprotein

Back 63

lipid portion and peptide portion

Front 64

lipoprotein attaches here

Back 64

inner leaflet of outer membrane, to peptidoglycan

Front 65

klebsiella and pneumococcus are surrounded by this slimy, wet material

Back 65

capsule

Front 66

bacteria with a capsule form this

Back 66

mucoid colony because they are all slimy and wet

Front 67

capsule made of this

Back 67

polysaccharide, repeating units of 2-3 sugars many times over, therefore its antigenic (K antigen), can do the same with typing sera

Front 68

how to visualize the capsule

Back 68

light microscope - negative staining with india ink - very dark, does not penetrate capsule
Quellung reaction - capsule swelling procedure - treat bact with antibody that causes them to swell and become visible

Front 69

two roles of bacterial capsule

Back 69

protection - against drying, bacteriophage infection, and phagocytosis
adhesion - help bacterium adhere to surface ex- S. mutans causes tooth decay - stick to enamel, produce acid that causes tooth decay

Front 70

is capsule good or bad?

Back 70

good for bact because it resists phagocytosis
bad for humans because it stays around longer
capsule is a virulence factor

Front 71

two ways to visualize motility of flagella

Back 71

hanging drop technique - put cell on coverslip, inverted over depression slide
semisolid agar - in a test tube, insert bacteria into a line, and incubate, it will either grow in a line or move all over

Front 72

why flagellum are hard to visualize

Back 72

long and narrow

Front 73

two ways to visualize flagellum

Back 73

stain with tannic acid that precipitates on it and makes it thicker and visible
dark-field microscopy

Front 74

number and location of flagellum

Back 74

polar - single or two flagella at one end
peritrichous - many flagella all over organism, exhibits swarming growth (concentric circles)

Front 75

3 parts of flagella

Back 75

filament - long whip like extension (antigenic)
hook - closer to cell, passes through a series of rings
basal body

Front 76

four rings that the filament of flagella pass through in the hook

Back 76

L ring - outer layer of cell
P ring - in peptidoglycan layer
S ring - in periplasmic space
M ring - in cytoplasmic membrane

Front 77

special case of flagella

Back 77

spirochetes - no flagella, have axial filaments that wrap around spiral-shaped body of cell and rotate, exist only in periplasmic space. when they rotate, the entire cell rotates like a corkscrew - can get through more viscous medium

Front 78

thinner, straighter and shorter than flagella

Back 78

pili

Front 79

two types of pili

Back 79

sex pili (1-4 per cell)
common pili (100-200 per cell)

Front 80

function of pili

Back 80

adhesion

Front 81

transfer of plasmid from male to female

Back 81

conjugation

Front 82

piece of extrachromosomal DNA, in cytoplasm, self replicating

Back 82

plasmid

Front 83

extrachromosomal piece of DNA which has ability to transfer from one cell to another via sex pilus

Back 83

F Factor

Front 84

what is the role of sex pili

Back 84

allow male and female cell to connect so that an F factor can be transferred (conjugatoin) from male to female

Front 85

purpose of common pili

Back 85

so cells can attach to human cells, without the ability to adhere to the target tissue bacteria would not be pathogenic

Front 86

two examples of common pili and why they are needed

Back 86

gonococcus causes gonorrhea, but if it doesnt have pili it is harmless
entropathic e coli - only ones with pili can colonize in the intestine

Front 87

three typing sera

Back 87

H antigen of flagella
O antigen of lipopolysaccharide
K antigen of capsule

Front 88

structure responsible for protein synthesis

Back 88

ribosome

Front 89

on the mRNA you can have many ribosomes, like beads on a string which speeds up the number of proteins synthesized. this is called

Back 89

polyribosomes

Front 90

in a rapid growth medium, how many ribosomes are there

Back 90

many

Front 91

in a poor growth medium, how many ribosomes are there

Back 91

few

Front 92

various proteins and enzymes in the membrane that carry out electron transport and oxidative phosphorylation

Back 92

mitochondria-like particles

Front 93

where the DNA of the cell is

Back 93

nucleoid

Front 94

DNA contains lots of phosphates with negative charges, so how is DNA compacted?

Back 94

polyamine molecules called putrseine and sperimidine are positive molecules that nuetralize the charges and aid in folding

Front 95

food reserves

Back 95

storage granules

Front 96

glycogen storage granules

Back 96

polysaccharides - found in enteric organisms (gut)

Front 97

lipid material storage granules

Back 97

poly - beta - hydroxy butyrate - found in bacillus, pseudomonis

Front 98

polyphosphate storage granules

Back 98

volutin granules - demonstrate and show metachromatic stain

Front 99

stain that shows one color when on shelf in bottle, shows another when reacts with volutin

Back 99

metachromatic stain
2 examples
1. dyptheria
2. tuberculosis

Front 100

three transport problems

Back 100

thermodynamic barrier - charged molecules can't cross membrane because two polar regions
concentration - bact have to scavenge molecules to get nutrients, and hold them in cell at higher concentration than outside
molecules extruded - cell needs to pump molecules out against concentration gradient

Front 101

transport system that requires no energy

Back 101

facilitated diffusion

Front 102

what transports molecules across a membrane

Back 102

carrier protein

Front 103

facilitated diffusion of water done by this

Back 103

aquaporins

Front 104

source of energy for active transport

Back 104

proton motive force (chemiosmotic theory) - protons extruded from membrane, making outside more acidic (high electric potential) - protons want to come back in, this energy used for transport

Front 105

transport in which substrate becomes phosphorylated

Back 105

group translocation

Front 106

phosphotransferase system AKA

Back 106

group translocation

Front 107

what source of energy is used in group translocation

Back 107

comes from PEP phosphoenolpyruvate - a high energy molecule similar to ATP

Front 108

two protein transport problems

Back 108

getting protein through membrane
orientation

Front 109

tag on the N terminal of a protein that maintains orientation

Back 109

signal peptide

Front 110

says that for proteins destined to be excreted from cell, there is a sequence at N terminal end of about 30 AA

Back 110

signal hypothesis

Front 111

a protein in the cytoplasm that recognizes the signal peptide and attaches to the peptide as its being made

Back 111

signal recognition particle

Front 112

happen when a bacterial cell comes into close proximity of host cell and literally injects the exotoxin into the host

Back 112

type III secretions

Front 113

human counterparts to bacterial protein transfer systems

Back 113

1. uptake of small molecules from blood
2. protein transport into ER from golgi, and since ER is continuous with nuclear membrane, same process occurs

Front 114

2 special cases of protein transport

Back 114

porins - molecular strainer/sieve that only allows certain molecules through; porin channels are composed of at least 3 proteins to make the transmembrane space
2. periplasmic binding proteins - proteins in periplasmic space have high affinity for particular molecules, they scavenge, assist with transport proteins in membrane, allow transfer of proteins into the cell, use ATP
3. iron transport - siderophores are secreted from cell, have high affinity for iron; repceptors in outer membrane bind these Fe-siderophore complexes

Front 115

iron is critical part of cells because needed for...

Back 115

cytochromes

Front 116

a protective, defensive form of the cell for when conditions are not favorable

Back 116

spore

Front 117

reverse of sporulation

Back 117

germination

Front 118

spores are resistant to

Back 118

drying, heat, freezing, toxic chemicals, radiation, poor nutrient supply

Front 119

process of spore formation

Back 119

mother cell (vegetative) elongates, forms spore septum making the forespore

Front 120

3 parts of the spore

Back 120

core
cortex
protein coat

Front 121

in core of spore, there is very little ....., amount of .......... is dramatically decreased, but all solid contents are there so its dense; increase in these polymers; synthesis of a spore-specific molecule called......; increase in this proton

Back 121

very little metabolic activity
amount of water dramatically decreased
increase in storage polymers esp poly - beta - hydroxybutyrate
dipicolinic acid
increase in calcium

Front 122

cortex of a spore has this structure

Back 122

peptidoglycan like

Front 123

how much crosslinkage in cortex of spore

Back 123

about six percent, very little, so it shrinks

Front 124

dehydration of spore is aided by shrinkage of the cortex and the presence of this

Back 124

calcium, which intercalates into DNA and displaces water molecules

Front 125

this change occurs in the protein coat of a spore

Back 125

becomes keratin like, making it tough and resistent, highly crosslinked with many disulfide bonds

Front 126

thermal resistance of a spore is due to this

Back 126

less water

Front 127

chemical and radiation resistance of spore due to this

Back 127

protein coat being thick and keratinized

Front 128

why is radiation harmful to a cell

Back 128

radiation reactions with medium to cause superoxides which are toxic

Front 129

three differences between spores

Back 129

1. aerobic vs anaerobic
2. location (terminal, subterminal, inside or outside cell)
3. shape (some circular, some oval)

Front 130

during sporulation, a change in this changes what genes are transcribed

Back 130

sigma factor, a protein that becomes part of RNA polymerase, and provides specificity, therefore a change in sigma factor is what changes which genes are transcribed

Front 131

two ways chemotaxis is similar to humans

Back 131

receptor proteins - cell surface proteins which function to transport molecules across the cytoplasmic membrane
transducer proteins - methylation of bacteria allows interpretation of whats coming in. all this is transmitted to basal body of flagellum and there is a motor response: flagellar rotation

Front 132

2 modes of bacterial mobility

Back 132

swimming and tumbling

Front 133

what causes mutants to swim toward repellant or away from attractant

Back 133

single point mutation

Front 134

disease in humans where you have an uncontrollable urge to eat your fingers; traced to single point mutation in purine synthesis

Back 134

Lesch Nyhan

Front 135

thermal resistance of a spore is due to this

Back 135

less water

Front 136

chemical and radiation resistance of spore due to this

Back 136

protein coat being thick and keratinized

Front 137

why is radiation harmful to a cell

Back 137

radiation reactions with medium to cause superoxides which are toxic

Front 138

three differences between spores

Back 138

1. aerobic vs anaerobic
2. location (terminal, subterminal, inside or outside cell)
3. shape (some circular, some oval)

Front 139

during sporulation, a change in this changes what genes are transcribed

Back 139

sigma factor, a protein that becomes part of RNA polymerase, and provides specificity, therefore a change in sigma factor is what changes which genes are transcribed

Front 140

two ways chemotaxis is similar to humans

Back 140

receptor proteins - cell surface proteins which function to transport molecules across the cytoplasmic membrane
transducer proteins - methylation of bacteria allows interpretation of whats coming in. all this is transmitted to basal body of flagellum and there is a motor response: flagellar rotation

Front 141

2 modes of bacterial mobility

Back 141

swimming and tumbling

Front 142

what causes mutants to swim toward repellant or away from attractant

Back 142

single point mutation

Front 143

disease in humans where you have an uncontrollable urge to eat your fingers; traced to single point mutation in purine synthesis

Back 143

Lesch Nyhan

Front 144

a protective, defensive form of the cell for when conditions are not favorable

Back 144

spore

Front 145

reverse of sporulation

Back 145

germination

Front 146

spores are resistant to

Back 146

drying, heat, freezing, toxic chemicals, radiation, poor nutrient supply

Front 147

process of spore formation

Back 147

mother cell (vegetative) elongates, forms spore septum making the forespore

Front 148

3 parts of the spore

Back 148

core
cortex
protein coat

Front 149

in core of spore, there is very little ....., amount of .......... is dramatically decreased, but all solid contents are there so its dense; increase in these polymers; synthesis of a spore-specific molecule called......; increase in this proton

Back 149

very little metabolic activity
amount of water dramatically decreased
increase in storage polymers esp poly - beta - hydroxybutyrate
dipicolinic acid
increase in calcium

Front 150

cortex of a spore has this structure

Back 150

peptidoglycan like

Front 151

how much crosslinkage in cortex of spore

Back 151

about six percent, very little, so it shrinks

Front 152

dehydration of spore is aided by shrinkage of the cortex and the presence of this

Back 152

calcium, which intercalates into DNA and displaces water molecules

Front 153

this change occurs in the protein coat of a spore

Back 153

becomes keratin like, making it tough and resistent, highly crosslinked with many disulfide bonds