Bacterial Structure & Function

Question 1

What does TLR 5 sense?

Answer 1

-Flagellin

Question 2

Which TLR’s can sense ss/ds RNA/DNA of viruses and bacteria?

Answer 2

TLR 3, 7, 8, 9

Question 3

Which TLR’s sense various membrane/wall components of gram + bacteria, mycobacteria, and yeast?

Answer 3

TLR 1, 2, 6

Question 4

What is the structure of gram-negative bacteria?

Answer 4

Contain an inner membrane, surrounded by a thin cell wall that is encompassed by an outer membrane

Question 5

What is the structure of gram-positive bacteria?

Answer 5

-single membrane surrounded by a thick cell wall

Question 6

What is the mechanism of action of Vancomycin?

Answer 6

• it binds to C-terminal D-Ala-D-Ala of late peptidoglycan (gram +) precursors
• prevents reactions catalyzed by transglycosylases, transpeptidases, and the D,D-carboxypeptidases

Question 7

How does LPS act as an endotoxin?

Answer 7

-in the bloodstream it can contribute to sever immune response resulting in septic shock

Question 8

What portion of LPS can be modified to resist cationic peptide antibiotics?

Answer 8

-Lipid A moiety

Question 9

What are the three main moieties of LPS?

Answer 9

• O-antigen
• Core Sugars
• Lipid A

Question 10

What is flagellin?

Answer 10

• the protein that makes up the filament portion of the flagellum
• ligand for TLR5

Question 11

What are the 5 common molecular targets of antibiotics in bacteria?

Answer 11

• Ribosomes
• RNA synthesis
• DNA gyrase
• Cell wall
• Folate Metabolism

Question 12

What is a metatranscriptome?

Answer 12

-a collection of genes expressed in an environment

Question 13

What is a pan-genome?

Answer 13

-a set of genes found in a particular bacterial species

Question 14

How do bacteria develop resistant to vancomycin?

Answer 14

-Replace an alanine on peptidoglycan with lactate or serine