week 3

Question 1

gram positive bacteria has?

Answer 1

teichoic acid

Question 2

types of secretion systems

Answer 2

Type I - spans whole membrane/outer membrane

Type II - spans membrane/outer membrane BUT takes proteins from sec or tat transporter

Type V- only spans outer membrane and takes proteins from sec or tat

Type III - spans the whole membrane/outer membrane + membrane of another cell to inject a protein

Type IV - injects DNA into another host cell - horizontal gene transfer

Type VI - has a sheath that retracts and contracts to act like a needle and secrete protein into a host cell

Question 3

S-layers

Answer 3

crystalline layer of glycoproteins outside of cell envelope
- provides protection against bacteriophages, low pH, lytic enzymes.

Question 4

Capsules

Answer 4

really long polysaccharides
- provide protection against other bacteria, immune systems, desiccation etc..

Question 5

Glycocalyx

Answer 5

LPS? teichoic acid
S-layer glycans
capsule
alginate
poly-N-acetylglucosamine
Enterobacterial common antigen
cellulose

all help with attachment or protect

Question 6

what are pili made out of

Answer 6

made of protein
thin filamentous structures

Question 7

what do pili do?

Answer 7

help in cell motility
- are retractable and can extend from the surface of the cell

Question 8

where are pili found?

Answer 8

found in all gram negative bacteria and many gram positive bacteria

Question 9

Types of pili

Answer 9

1. fimbrae
2. conjugation
3. electrically conductive pili
4. type IV pili (involved in motility, one of the secretion systems)

Question 10

Motility on solid surfaces ?

Answer 10

a.) twitching
b.) gliding

Question 11

motility on semi-solid surfaces

Answer 11

swarming
- uses flagella
- coordinated movement

Question 12

swimming motility
- flagella

Answer 12

a.) peritrichous b. polar c. lophotrichous

Question 13

flagella parts

Answer 13

1. hollow tip that is built from the bottom
2. rotor part that spins
3. stationary part in peptidoglycan to anchor flagella

Question 14

what does bacteria flagella use as a power source?

Answer 14

proton motor pump/force

Question 15

CCW = ?

Answer 15

cell runs

Question 16

CW = ?

Answer 16

cell tumbles

Question 17

CW = ? (in reversible flagella)

Answer 17

cell reverses

Question 18

chemotaxis

Answer 18

directed movement of bacteria in a chemical gradient

Question 19

Archaea membranes

Answer 19

-no phosphate
- more stable

Question 20

Archaea cell envelope

Answer 20

NO peptidoglycan !!
- some have pseudomurein which is similar
- some have S layer or protein sheath

Question 21

Pseudomurein

Answer 21

has a lyzosozyme insensitive bond between the sugars. B(1,3)

has N-acetlyalosaminuronic acid for a sugar

Question 22

Archaea flagella

Answer 22

smilar to bacteria flagella but uses ATP as energy source

Question 23

Archaea hami

Answer 23

unique attachment structure

Question 24

Lag phase

Answer 24

nutrients are being internalized
enzymes are being made
replication of cellular components

Question 25

Exponential phase

Answer 25

population growth is doubling as fast as possible (optimal growth) linear under log scale

Question 26

stationary phase

Answer 26

running out of nutrients growth slows some cells die NO net increase in cell numbers - synthesis of endospores

Question 27

death phase

Answer 27

rupture of plasma membrane destruction of DNA

Question 28

Asexual reproduction

Answer 28

binary fission budding fragmentation

Question 29

cytokinesis

Answer 29

replication of cytoplasmic contents - septation occurs (cross walls between daughter cells) - site is selected by FtsZ (in center of cell) - z ring is assembled - linked to p. membrane - constriction of cell and septum formation

Question 30

e. coli divisome

Answer 30

10,000 FtsZ molecules polymerize into a ring in the center of the cell - ring is tethereto P.M by ZipA and FtsA - localizes peptidoglycan biosynthesis machinery to center of cell

Question 31

how does the cell know where the centre is for Z ring formation?

Answer 31

MinCD prevnts Z ring from forming - where MinE is = no MinCD = ring can fotm - after septum forms - MinCD comes back

Question 32

where does peptidogylcan synthesis occur?

Answer 32

in the middle of the cell- anchored by the FtsZ ring

Question 33

Peptidogylcan biosynthesis

Answer 33

1. synthesis of building blocks 2. synthesis of disaccharide-peptide repeat unit 3. translocation = cytoplasm to periplasm 4. transglycosylation = formation of glycan linkages 5. transpeptidation = peptide cross linkages

Question 34

translocation

Answer 34

moving repeat building blocks from cytoplasm to periplasm

Question 35

transglycosylation

Answer 35

= formation of glycan linkages

Question 36

transpeptidation

Answer 36

= formation of = peptide cross linkages