Microbial metabolism Flashcards Preview

Year 1 Microbiology > Microbial metabolism > Flashcards

Flashcards in Microbial metabolism Deck (25):
1

Lag phase?

1. Initial period of adaptation to a new environment2. Increase in metabolic activity3. Sensitive to antimicrobials4. Little to no cell division

2

During what stage(s) are bacteria susceptible to antimicrobials?

1. Lag2. Exponential

3

Exponential phase

1. Rapid multiplication by binary fission2. Most susceptible to antibiotics

4

Stationary phase

1. Nutrients depleted, waste products accumulate2. Decreased growth rate3. Spore forming bacteria initiate sporulation

5

During what growth phase do spore forming bacteria begin sporulation?

Stationary phase

6

Decline phase

More bacteria die than are generated

7

Obligate aerobe

Bacteria that require oxygen and metabolize by respiration

8

Obligate anaerobe

Bacteria that are inhibited or killed by oxygen and utilize fermentation exclusively for energy production

9

Facultative anaerobe

1. Bacteria that grow well under aerobic or anaerobic conditions. If oxygen is available they respire, if not they use fermentation2. Majority of bacteria

10

Microaerophilic

Require 5-10% oxygen for optimal growth

11

What does catalase (or peroxidase) do?

Breaks down H2O2 into O2 and H2O

12

What does superoxide dismutase do?

Detoxifies O2- to H2O and O2

13

What must bacteria synthesize to make nucleic acids, making it a target for antibiotics?

Folate

14

What do quinolones target?

DNA gyrase

15

What drug class targets DNA gyrase?

Quinolones

16

What does rifampin target?

Bacterial DNA-dependent RNA polymerase

17

What is the precursor subunit of peptidoglycan?

UDP-N-acetyl muramic acid

18

Where is UDP-N-acetyl muramic acid synthesized?

Bacterial cytoplasm

19

What is added to the 3rd carbon of UDP-N-acetyl glucosamine to make UDP-N-acetyl muramic acid?

Lactyl group

20

What occurs once UDP-NAM is made?

5 amino acids are added to it

21

What happens to the UDP-NAM-pentapeptide after it is formed?

Transferred from UDP to bactoprenol phosphate at membrane surface

22

What happens to bactoprenol-NAM-pentapeptide to form the final disaccharide-pentapeptide precursor product?

NAG is transferred from UDP-NAG to it

23

How are the peptide side chains linked together?

Transpeptidation

24

What is transpeptidation?

1. Cross linking of peptide chains by peptide bond exchange2. Occurs on outer leaflet of plasma membrane

25

Where does transpeptidation occur?

Outer leaflet of plasma membrane