Bacterial Structure and Function

Question 1

Defining characteristics of bacteria

Answer 1

intronless circular DNA genome localized to the nucleoid, 70S ribosomes, peptidoglycan cell wall, reproduction by binary fission

Question 2

all bacteria have

Answer 2

internal plasma membrane

Question 3

mycolic acid layer

Answer 3

of acid fast bacteria resist both crystal violet and counterstain

Question 4

gram stain

Answer 4

fix, crystal violet, iodine, decolorize, counterstain (usually safranin)

Question 5

Gram (+)

Answer 5

thick peptidoglycan wall holds crystal violet

Question 6

Three surface structure with medical implications

Answer 6

LPS of Gram (-), Glycocalices, Pili

Question 7

bacterial flagella

Answer 7

rotating corkscrews powered by transmembrane electron gradients and used for propulsion, not whiplike

Question 8

bacterial ribosomes

Answer 8

smaller and sediment less readily under ultracentrifugation than eukaryotic ones

Question 9

bacterial spores

Answer 9

formed when certain bacteria (bacillus, clostridium) become nutrient depleted. contains genome with minimal macromolecules. unpacks when nutrients and water become available.

Question 10

bacterial reproduction

Answer 10

by binary fission. undergoes exponential growth when provided with unlimited nutrients and waste removal. enter predictable pattern of lag, log, stationary, and death phases

Question 11

bacterial tolerance for oxygen

Answer 11

determined by ability to detoxify radicals. molecules like oxidase, superoxide dismutase, catalase and cytochrome are protective.

Question 12

bacteria dependence on oxygen

Answer 12

determined by their need for it as a terminal electron acceptor for respiration.

Question 13

facultative anaerobes

Answer 13

encodes pathways for both fermentation and respiration