Microbial Metabolism

Question 1

Binary Fission

Answer 1

exact copy of genome is made

single cell divides into 2 daughter cells

Question 2

4 phases of bacterial metabolism

Answer 2

Lag phase
Exponential phase
Stationary phase
decline

Question 3

What stages are sensitive to antimicrobials

Answer 3

lag and exponential phase

Question 4

What stage is less sensitive to antimicrobials

Answer 4

stationary phase

Question 5

What phase does sporulation take place?

Answer 5

stationary phase

Question 6

What are some things that can affect bacterial growth

Answer 6

pH
aerobic vs/ anaerobic
nutrients/composition of media
temperature

Question 7

Aerobic

Answer 7

exclusively uses respiration to meet its energy need

Need oxygen to live

Question 8

How do aerobic cells counter hydrogen peroxide?

Answer 8

catalase

Question 9

How do aerobic cells counter superoxide?

Answer 9

SOD

Question 10

Anaerobic

Answer 10

exclusively use fermentation to meet its energy needs
killed by oxygen
can have anaerobic respiration

Question 11

Anaerobic respiration

Answer 11

inorganic compounds other than molecular oxygen serve as terminal electron acceptors

Question 12

Facilitative anaerobes

Answer 12

can respire or ferment

Question 13

What do facilitative anaerobes contain?

Answer 13

catalase

superoxide dismutase

Question 14

Microaerophilic

Answer 14

grow best at low oxygen, but can grow without it as well

Question 15

What do microaerophilics contain?

Answer 15

catalase

superoxide dismutase

Question 16

Fermentation

Answer 16

pyruvate is converted to various end products

Question 17

Nucleic acid biosynthesis

Answer 17

agents that selectively inhibit microbial nucleic acid biosynthesis are imporant

Question 18

What is essential in the synthesis of purines and thymidine

Answer 18

folate

Question 19

What is folate derived from in bacteria?

Answer 19

PABA

Question 20

Where does folate come from in peoples?

Answer 20

foodstuffs

Question 21

Bacterial cell wall biosynthesis

Answer 21

i. Activate carbohydrate subunits
ii. A pentapeptide is added to UDP-NAM
iii. UDP-NAM-pentapeptide is attached to the bacterprenol through a pyrophosphate link with the release of UMP
iv. NAG is added to NAM-pentapeptide bactroprenol complex
v. Bactoprenol carrier transports the completed NAG-NAM pentapeptide repeat unit across the membrane
vi. Disaccharide unit is attached to the end of the growing peptidoglycan chain by enzymes called transglycosylases
vii. Pyrophosphobactoprenol is converted back to phosphobactoprenol and recycled