intro- bailey

Question 1

what type of bacteria can grow in both aerobic and anaerobic environments?

Answer 1

Facultative anaerobes

Question 2

which class of aerobes are most important to medicine?

Answer 2

facultative anaerobes

Question 3

under what conditions to Oligotrophs grow? Microaerophiles? Mesophiles?

Answer 3

Oligotrophs- can grow with limited nutrients
Microaerophiles- requires low oxygen levels
Mesophiles- grow well in mild temperatures

Question 4

what type of bacteria have a thick layer of peptidoglycan?

Answer 4

gram-positive

Question 5

what is the general structure of Murein?

Answer 5

long strands of N-acetylmuramic acid and N-acetylglucosamine
-all cross-linked with peptides

Question 6

what is NAM? where is it found?

Answer 6

1) N-acetly muramic acid

2) found on gram-positive bacteria

Question 7

where are NAG and NAM produced? where does elongation occur?

Answer 7

1) in the bacterial cytoplasm

2) elongation occurs in the periplasmic space

Question 8

what 2 acids are found on the outer surface of gram+ bacteria? (outer layer of the cell wall)

Answer 8

Teichoic acid and lipoteichoic acid

Question 9

what is the outer layer of gram negative bacteria?

Answer 9

LPS- lipopolysaccharide

Question 10

where do teichoic acids attach on the cell wall? lipoteichoic acids?

Answer 10

teichoic acids- attach to NAG and NAM

lipoteichoic acids- extend into lipid membrane

Question 11

what are the 3 regions of a LPS molecule?

Answer 11

from internal to external:

1) Lipid A
2) Polysaccharide core
3) O-antigen

Question 12

which subunit on LPS shows the most variability?

Answer 12

the O-antigen

Question 13

what substance is produced in response to LPS? (hint: causes toxic shock syndrome)

Answer 13

TNF-alpha

Question 14

what receptor recognizes LPS?

Answer 14

Toll-like receptor 4 (TLR4)

Question 15

what receptor recognizes peptidoglycan?

Answer 15

Toll-like receptor 2 (TLR2)

Question 16

which receptor recognizes teichoic acids?

Answer 16

toll-like receptor 2

Question 17

name the other 3 extracellular structures

Answer 17

1) flagella
2) Pili (fimbriae)
3) glycocalyx

Question 18

what structure involved in the attachment of bacteria to other surfaces?

Answer 18

Pili (fimbriae)

Question 19

what are Adhesins?

Answer 19

specilized proteins on the tips of fimbriae. Made specifically for adhesion to other surfaces/cells

Question 20

what are the 3 classes of flagella?

Answer 20

1) monotrichous
2) Lophotrichous
3) Peritrichous

Question 21

name the 4 basic structures of a flagella/fimbriae

Answer 21

Filament, Hook, rod, movement proteins

Question 22

what is taxis?

Answer 22

directed movement toward/away from a stimulus

Question 23

name the 4 types of taxis

Answer 23

1) chemotaxis
2) Aerotaxis
3) Osmotaxis
4) Thermotaxis

Question 24

what is a capsule

Answer 24

a well-organized, firmly attached Glycocalyx

Question 25

what is a slime layer?

Answer 25

a glycocalyx that is not firmly attached or well-organized

Question 26

how can a capsule act as a virulence factor for bacteria?

Answer 26

They can hide the cell from our bodies immune system, or create a large/bulky covering that makes it difficult for microphages to ingulf them

Question 27

which cytokines are released when a bacteria is recognized?

Answer 27

IL-1, IL-12, TNF-alpha

Question 28

name the 2 classes of bacterial pathogens

Answer 28

Opportunistic and Primary

Question 29

name the 2 types of non-specific adherence

Answer 29

Reversible and Docking

Question 30

give examples of docking adherence

Answer 30

1) Browning's movements (random interactions) 2) electrostatic attractions 3) interaction with glycocalyx

Question 31

what does specific adherence require?

Answer 31

adhesins

Question 32

what do the adhesins of streptococcus mutans bind to?

Answer 32

the pellicle of teeth

Question 33

what adhesin is not found on fimbrae?

Answer 33

Fibronectin- found in plasma

Question 34

how do bacteria "take up" nutrients?

Answer 34

1. Carrier-mediated diffusion (facilitated) 2. Phosphorylation-linked transport (group translocation) 3. Active transport (energy dependent)

Question 35

what is Enteropathogenic E. coli (EPEC) a prime example of?

Answer 35

colonization inducing tissue pathology- leads to actin polymerization

Question 36

what are the 2 main mechanisms for bacterial colonization/invasion?

Answer 36

secretion of hyaluronidase and collagenase.

Question 37

Endotoxins:

Answer 37

Not secreted. They are on the surface of the bacterium. | Lipopolysaccharide is the most common (that’s why people call it endotoxin).

Question 38

Exotoxins

Answer 38

Exotoxins are diffusible proteins that are secreted. 3 main types (type 1, 2, 3)

Question 39

what makes a microbe a pathogen?

Answer 39

``` Ability to adhere to host. Ability to colonize the host. Ability to replicate within given niche. Ability to cause damage. Invasion Production of toxin Activation of the immune system ```