Lecture 3: Bacterial Structure And Function 2

Question 1

Are bacteria flagella whiplike, or rotating corkscrews?

Answer 1

Rotating corkscrews

Question 2

What are bacteria flagella powered by?

Answer 2

Transmembrane electron gradients

Question 3

What do bacteria use flagella for?

Answer 3

Propulsion

Question 4

Are bacterial ribosomes smaller or larger than human ribosomes? Do they sediment more or less readily?

Answer 4

Smaller (B=70S, human=80S)

Sediment less readily

Question 5

What makes bacterial ribosomes attractive antibiotic targets?

Answer 5

Chemical differences

Question 6

What are some chemicals present in bacterial ribosomes that are targeted by antibiotics?

Answer 6

Aminoglycosides
Tetracyclines
Macrolides

Question 7

What structures set the standard for autoclaving?

Answer 7

Endospores

Question 8

What are distinguishing features of endospores?

Answer 8

rugged, dehydrated
contains all of genome
contains minimal macromolecules

Question 9

Which growth phase accompanies unlimited nutrients and waste removal?

Answer 9

Exponential growth

Question 10

What growth pattern emerges in a culture vessel of limited size?

Answer 10

Lag, log, stationary, death

Question 11

What protective molecules must aerobic bacteria contain?

Answer 11

oxidase
superoxide dismutase
catalase
cytochrome

Question 12

How are bacteria classified if thet lack oxidase, superoxide dismutase, catalase, and cytochrome?

Answer 12

Obligate anaerobes

Question 13

How do obligate anaerobes derive ATP?

Answer 13

Fermentation

Question 14

What determines bacteria’s dependence on oxygen?

Answer 14

their need for oxygen as a terminal electron acceptor for respiration

Question 15

What are bacteria which cannot ferment called?

Answer 15

Obligate aerobes

Question 16

What are bacteria which encode pathways for both fermentation and respiration?

Answer 16

Facultative anaerobes

Question 17

Quorum sensing allows bacteria to sense ________ and alter ________ accordingly

Answer 17

sense population density

alter genetic expression

Question 18

What are the three molecules needed in quorum sensing?

Answer 18

Inducer (secreted)
Receptor (for inducer)
Transcriptional Activator (responds to high intracellular levels of Inducer)

Question 19

What two characteristics make quorum sensing in medicine?

Answer 19

Biofilms

Coordinated expression of toxins