Lecture 6-7 (Cell Structures)

Question 1

What type of molecule can a bacterium use to stabilize its membrane at really high temperatures?
A. Unsaturated fatty acids
B. Short chain fatty acids
C. Hopanoids
D. Branched chain fatty acids

Answer 1

C.

Question 2

What type of linkages would you expect between the NAM and NAG monosaccharides in peptidoglycan?
A. Alpha linkages
B. Beta Linkages
C. Delta Linkages
D. Gamma Linkages

Answer 2

B.

Question 3

What happens when a red blood cell is in Hypotonic solution what happens?
A. Nothing
B. Crenation
C. Lysed
D. Water flows out of the cell

Answer 3

C.

Question 4

What type of enzyme is important for peptidoglycan cross-linking?
A. Ribosome
B. DNA polymerase
C. Beta-lactam
D. Transpeptidase

Answer 4

D.

Question 5

Vancomycin is effective at blocking peptidoglycan cross-linking by binding what?
A. DAP
B. D-alanine
C. NAG-NAM polysaccharide
D. Transpeptidase

Answer 5

B.

Question 6

Teichoic acid in Gram-positive bacteria and the O-antigen in Gram-negative bacteria both create a protective charge barrier to protect the cell against some chemicals.
T/F

Answer 6

False, why? Because O-antigen’s function is UNKNOWN.

Question 7

Generally, A._________
cells have a thicker peptidoglycan layer, while
B.____________
cells are surrounded by a secondary outer membrane containing endotoxin.

Answer 7

A. Gram Positive
B. Gram Negative

Question 8

Membrane invaginations are closed-off completely.
T/F

Answer 8

False

Question 9

What enzyme breaks existing beta-linkages between NAG-NAM monomers, part of the innate immune system, and is also found in egg shells?

Answer 9

Lysozyme

Question 10

You have a Patient with a bacteremia, the presence of a viable bacteria in the circulating blood. Your Diagnosis is Klebsiella, a Gram Negative pathogen.
Your Treatment is Amoxicillin (a beta-lactam), it appears to be effective against the culture, Should you treat it? And why?

Answer 10

NO, It is a Gram Negative that has Endotoxins. You should treat them with a antibiotic that doesn’t lyse the cell.

Question 11

What Protein(s) in the peptidoglycan forms
A. a Rod shape
B. a Vibro shape
C. Coccus shape

Answer 11

A. MreB
B. MreB & CreS
C. FtsZ

Question 12

What groups of bacteria (Gram Neg/Pos) would be more likely susceptible to antibiotics that target
1. LPS
2. Peptidoglycan

Answer 12

1. Gram Negative (They have the lipopolysaccharides to attach to)
2. Gram Positive (they have a thicker Peptidoglycan later)

Question 13

Biofilm formation is more dependent on the production of which of the following?
A. EPS
B. LPS
C. Endospores
D. S-layer

Answer 13

A.

Question 14

The 1.______ of bacteria are typically anchored to the cell, while the 2._________ is loosely associated but both structures are made of extracellular polysaccharides (EPS).
Drop box options:
EPS
LPS
Capsule
Slime layer
S-Layer

Answer 14

1. Capsule
2. Slime layer

Question 15

In the COLD, cells can do what of the following to keep functioning?
A. Less Saturated fatty acids
B. More Branching
C. Long fatty acid tails
D. All of these

Answer 15

D.

Question 16

The S-Layer is not essential to all bacteria and functions as physical armor.
T/F

Answer 16

True

Question 17

What are the two types of EPS?

Answer 17

1. Capsule
2. Slime Layer

Question 18

What signals EPS to stop motility and begin expression?

Answer 18

cyclic-di-GMP

Question 19

Mycolic acid is an internal structure?
T/F

Answer 19

False

Question 20

What are the 3 domains of the LPS?

Answer 20

1. O-Antigen
2. Core
3. Lipid A

Question 21

LPS is positively charged to repel hydrophobic molecules. And is Only found in Gram Negative bacteria.
T/F

Answer 21

False. Why, because it is Negatively charged. Everything else is correct.