Mid Term 1 Review Questions (Part 2.1)

Question 1

light vs. electron microscopy

Answer 1

LIGHT: uses light and lenses. magnifies 1000x. cell size, shape, and MOTILITY.
ELECTRON: uses electrons, not light, 100,000x magnification. can’t see living things.

Question 2

what does pleomorphic mean?

Answer 2

varying in shape

Question 3

what does monomorphic mean?

Answer 3

one form or shape

Question 4

what is a capsule?
what is it also called?
what is it made of?

Answer 4

outer layer of prokaryotic cell. glycocalyx. shell of sugars.

Question 5

what role does a capsule play in pathogenesis?

Answer 5

waves HAEEE
helps pathogens
1. HIDE
2. ADHERE
3. ESCAPE PHAGOCYTOSIS

Question 6

how can we identify capsulated bacteria? (2)

Answer 6

1.they form shiny slimy colonies on solid media
2. stains

Question 7

what is the purpose of the cell wall? (2)

Answer 7

1. provide rigidity to the cell
2. keep it from bursting

Question 8

describe the location of the bacterial cell wall

Answer 8

capsule surrounds cell wall surround cytoplasmic membrane

Question 9

name two places where lysozyme can be found

Answer 9

tears, egg whites

Question 10

what is the medical significance of the bacterial cell wall? (3)

Answer 10

SLIT

1. target for selective toxicity (targeted by certain antibiotics)
2. target of lysozyme
3. recognized by the innate immune system (it’s a PAMP, MAMP)

Question 11

what are the steps of gram staining?

Answer 11

1. CV: both cells turn purple.
2. Iodine: CV sticks to G+, nothing happens to G-. CV is present but can be easily washed away by…
3. Alcohol: CV is trapped in G+, punctures outer membrane of G-, CV washes away. most important step and easiest to mess up.
4. Safranin: stains G- pink.

Question 12

In the name E. coli O157:H7, what does the O indicate?

Answer 12

O antigen in G- cell wall

Question 13

In the name E. coli O157:H7, what does the H indicate?

Answer 13

presence of flagella

Question 14

describe a G+ bacterial cell wall (4)

Answer 14

• thick layer of peptidoglycan (PAMP)
• teichoic acids
• gel-like material
• cytoplasmic membrane

Question 15

describe a G- bacterial cell wall (5)

Answer 15

• LPS (O antigen, lipid A) (ENDOTOXIN)
• Outer membrane (lipid bilayer) (porins)
• Periplasm
• Thin layer of peptidoglycan
• Cytoplasmic membrane

Question 16

what two elements make up LPS

Answer 16

¡hola!
O antigen and lipid A

Question 17

LPS stands for, and is also called

Answer 17

lipopolysaccharide. endotoxin

Question 18

name an example of a bacteria that lack a cell wall

Answer 18

mycoplasma species

Question 19

what shape do mycoplasma species take?

Answer 19

pleomorphic

Question 20

what provides rigidity in mycoplasma? where are they located?

Answer 20

sterols in the cytoplasmic membrane

Question 21

what staining is used in mycobacteria? why?

Answer 21

acid fast. no cell wall!

Question 22

what are three special facts about archaeal cell walls?

Answer 22

• variety of cell wall types
• no peptidoglycan
• have an S layer (some bacteria have an S layer too)

Question 23

cell membrane aka

Answer 23

cytoplasmic membrane

Question 24

cytoplasmic membrane aka

Answer 24

cell membrane

Question 25

what is the role of the cell membrane? (4)

Answer 25

- selective permeability - transporters - carriers - structural and sensor proteins are embedded in the cell membrane

Question 26

what is the role of the cytoplasmic membrane? (4)

Answer 26

Carrie transports her professional perm - selective permeability - transporters - carriers - structural and sensor proteins are embedded in the cell membrane

Question 27

what two general transport systems direct movement of molecules across the cytoplasmic membrane?

Answer 27

1. facilitated diffusion 2. active transport

Question 28

describe facilitated diffusion

Answer 28

No energy expended, goes with the concentration gradient

Question 29

describe active transport

Answer 29

energy expended (against concentration gradient)

Question 30

list one famous example of active transport?

Answer 30

efflux pump

Question 31

what do efflux pumps do? what type of transport system do they represent?

Answer 31

active transport, use energy, pump antibiotics out of the cell

Question 32

which secretion system have we studied so far in class?

Answer 32

type III

Question 33

Type III secretion system aka

Answer 33

injectisome

Question 34

Injectisome aka

Answer 34

Type III secretory system

Question 35

what is the role of T3SS? in other words, what is it important for and how?

Answer 35

important for virulence by causing changes in the host cell

Question 36

what happens if alcohol is not used for long enough during a gram stain?

Answer 36

G- does not lose CV and looks purple

Question 37

what happens if alcohol is used for too long during a gram stain?

Answer 37

peptidoglycan in G+ dries out and cracks, so the G+ loses its purple color