Module 2

Question 1

name the bacteria shapes

Answer 1

spherical (coccus, cocci)
rod-shaped (bacillus, bacilli)
comma-shaped (vibrio, vibrios)
spiral-shaped (spirillum, spirilla)
variable

Question 2

where would spiral-shaped bacteria be advantageous

Answer 2

viscous or turbulent aquatic environments

Question 3

what do rods or filaments (bacteria shape) indicate in terms of mobility

Answer 3

has a gliding motion along a surface

Question 4

what are some multicellular organizations for bacteria

Answer 4

hyphae (branching filaments of cells, rods)
mycelia (clump of hyphae)
trichromes (smooth, unbranched filament)

Question 5

what is a feature of the giant bacteria Epulopiscium fishelsoni

Answer 5

makes hundreds of copies or its genome and distributes it throughout the cell
in a nutrient rich environment (only in surgeonfish)

Question 6

what are some advantages of smaller cells

Answer 6

higher SA/V ratio
advantageous in low-nutrient environments where high-efficiency exchange is needed
grow and evolve faster

Question 7

how is DNA condensed in the nucleoid

Answer 7

the backbone is neutralized by being coated with cations
a molecular “glue” holds them together, small positively charged proteins
enzyme called topoisomerase nick the DNA strand, twisting it and reattaching it

Question 8

what are inclusion bodies

Answer 8

accumulations of C, N, S, or P storage compounds

Question 9

what is a use of sulfur globules

Answer 9

stored sulfur is used as a continued source of electrons

Question 10

what are some examples of carbon-storage compounds

Answer 10

starch
polyhydroxybutyrate (PHB)

Question 11

what are gas vesicles used for

Answer 11

buoyancy control

Question 12

define: carboxysomes

Answer 12

location of carbon fixation reactions
provides a location for RuBisco enzyme to operate (converts CO2 into organic carbon)

Question 13

define: magnetosomes

Answer 13

microcompartment that serves as an internal compass
made up of chains of magnetite
helps certain bacteria underwater move towards the surface of the sediment

Question 14

use: MreB protein

Answer 14

governs the overall shape of the cell (homologous to actin)

Question 15

use: FtsZ

Answer 15

forms a band that goes around the circumference of the cell during division
acts as an anchor for the cell division protein machinery to localize
homologous to tubulin

Question 16

use: par proteins

Answer 16

move copied components of the original cell into 2 separate zones

Question 17

what is included in the cell envelope

Answer 17

cytoplasmic membrane
cell wall
outer membrane

Question 18

what is the sterol equivalent in bacteria (in the plasma membrane)

Answer 18

hopanoid

Question 19

what is a protein that aids active transport

Answer 19

siderophores

Question 20

some roles of the cytoplasmic membrane

Answer 20

location for energy-capturing reactions
flagella anchoring
sensory systems location (detecting changing conditions)

Question 21

2 types of strands in the peptidoglycan layer

Answer 21

repeating glycan units strand
crosslinked peptide chains between glycan polymer strands

Question 22

peptide crosslink subunit structure

Answer 22

two sugars: N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)
peptide chains attach from a NAM to another NAM
not too many AA’s

Question 23

what is unique about the AA’s in the peptidoglycan layer

Answer 23

D-isomers are only found
diaminopimelic acid (DAP is only found here)

Question 24

formation of the cell wall

Answer 24

made of pentapeptide precursors which have a 5th AA

Question 25

how are pentapeptide precursors moved out the plasma membrane

Answer 25

movement is facilitated by lipid carriers that are hydrophobic and embedded in the plasma membrane: bactoprenol lipid

Question 26

what links are made for a pentapeptide precursor

Answer 26

1. b/w NAG of the precursor and NAM of the existing cell wall: transglycosylation 2. addition of a crosslink: transpeptidation

Question 27

how do lysozomes work

Answer 27

attack the glycosidic bonds that hold the peptidoglycan layer together able to generate cells w/ no walls in an isotonic solution

Question 28

how does penicillin work

Answer 28

binds to Ftsl to prevent the transpeptidation rxn used in rebuilding the cell wall

Question 29

what is lysostaphin used against

Answer 29

staphylcoccus aureus

Question 30

how do bacteria resist against B-lactam antibiotics

Answer 30

produce an enzyme that interferes with the lactam ring (β-lactamase)

Question 31

what is used to combat β-lactamase

Answer 31

clavulanic acid

Question 32

define: divisome

Answer 32

complex of cytoskeleton components and the enzymes responsible for breaking and reforming the cell wall

Question 33

use: Ftsl

Answer 33

enzyme that catalyzes the transpeptidation reaction

Question 34

what are protoplasts

Answer 34

cells with their wall removed and maintained stably

Question 35

how does lysostaphin work

Answer 35

cleaves the glycine interbridge that is found in the peptidoglycan layer

Question 36

describe Gram-positive bacteria

Answer 36

- thick cell wall - periplasmic space between the plasma membrane and cell wall

Question 37

what is contained in Gram-positive bacteria that is absent in Gram-negative bacteria

Answer 37

teichoic acids

Question 38

what do teichoic acids do

Answer 38

- hold the peptidoglycan layer together - anchors the wall to the cytoplasmic membrane

Question 39

define: lipoteichoic acids

Answer 39

teichoic acids that descend into the cytoplasmic membrane

Question 40

describe Gram-negative bacteria

Answer 40

- have thin walls - relatively large periplasm - have a second membrane outside of the cell wall made up of lipopolysaccharides

Question 41

are Gram positive or negative bacteria more common

Answer 41

Gram-negative

Question 42

what are the steps of a Gram stain

Answer 42

1. crystal violet 2. iodine 3. ethanol 4. safranin

Question 43

what does varying the O side chain in the outer membrane of Gram-negative bacteria do

Answer 43

evades host immune responses, acts as a cloaking layer against antibodies

Question 44

what component of the outer membrane is particularly immunogenic

Answer 44

lipid A

Question 45

how is water and other small nutrients transported across the outer membrane in the cell

Answer 45

porin proteins

Question 46

what is energy-requiring transport into the cell across the outer membrane catalyzed by

Answer 46

the TonB-dependent receptor and transport system

Question 47

define: autoproteins

Answer 47

proteins that have the ability to auto transport

Question 48

what are Type III secretion systems associated with

Answer 48

pathogenic organisms that transport polypeptides produced through a hollow tube across both membranes

Question 49

what type of bacteria can produce spores

Answer 49

Gram-positive

Question 50

what are spores made of

Answer 50

a thick peptidoglycan layer and then another layer of proteins

Question 51

what do spores have resistance to

Answer 51

- radiation - sunlight and UV - desiccation - heat - acids and bases

Question 52

what is germination

Answer 52

return of a spore to a vegetative state when conditions are favourable

Question 53

what are monotrichous flagella

Answer 53

single flagellum extending outwards

Question 54

what are amphitrichous flagella

Answer 54

one flagellum at each end

Question 55

what are lophotrichous flagella

Answer 55

tuft of flagella on one end

Question 56

what are peritrichous flagella

Answer 56

flagella all around the cell

Question 57

what are the 3 components of flagella

Answer 57

- filament - hook - basal body

Question 58

what does the hook do in a flagella

Answer 58

- connection between filament and basal body - acts like an arm turning a skipping rope

Question 59

what does the basal body do in a flagella

Answer 59

- serves as an anchor for attaching the flagellum to the bacterial cell - serves as motor that turns the flagellum

Question 60

what is the basal body in a flagella dependent on

Answer 60

proton motive force

Question 61

how do monotrichous flagella move bacteria

Answer 61

cell moves forward for turn in 1 direction, backwards for the other

Question 62

how do amphitrichous flagella move bacteria

Answer 62

the direction depends on which flagellum moves

Question 63

how do lophotrichous/peritrichous flagella move bacteria

Answer 63

- when all flagella rotate in a counter-clockwise direction, the cell moves forward - once a few flagella rotate clockwise they all disperse and the cell enters a tumble

Question 64

what is chemotaxis

Answer 64

means of moving in response to chemical gradients

Question 65

where are internal flagella located

Answer 65

in the periplasmic space

Question 66

how does gliding motility work

Answer 66

the bacteria smoothly slides over a surface by using small protein pedestals to grip on the surface and pull the bacteria forward

Question 67

what are myxobacteria

Answer 67

predatory bacteria that hunt other bacteria by moving along surfaces in little packs

Question 68

what does twitching motility utilize

Answer 68

pili, extensions that come from the surface and attach to surfaces

Question 69

what is the causative agent of dysentery

Answer 69

Shigella

Question 70

what are the tails of Shigella made of

Answer 70

the host cell's actin

Question 71

what is an example of an adherence molecule

Answer 71

pili

Question 72

what are 2 functions of stalks

Answer 72

1. attaching to surfaces 2. nutrition acquisition

Question 73

what are 3 advantages to capsules

Answer 73

1. can stick 2. evade the immune response of the host 3. avoid drying out

Question 74

what are capsules made of

Answer 74

thick polysaccharide layer surrounding the cell

Question 75

what are surface arrays made of

Answer 75

matrix of proteins outside the cell

Question 76

what are surface arrays used for

Answer 76

1. adhesion 2. protection against predation or infection

Question 77

what are fimbriae

Answer 77

alternative term to describe these adhesive pili

Question 78

what are "type strains"

Answer 78

the "typical" stain, first discovered or the gold standard