Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbio Test I > Lecture 2 > Flashcards

Lecture 2 Flashcards

1
Q

True or False: metabolic differences between bacteria and eukaryotes can be utilized for the development of antibacterial therapies.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Binary fission

A

an exact copy of the genome is made and a single cell divides into 2 binary daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

when are bacteria sensitive to antimicrobials? why?

A

lag phase and exponential phase

- sensitive to antimicrobials because they are metabolizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when are bacteria less sensitive to killing by antimicrobials

A

stationary phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why does the stationary phase occur?

A

at stationary phase they have either used up nutrients or built up toxic metabolites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

during which phase does sporulation occur?

A

stationary phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the minimum requirement for growth?

A

source of carbon and nitrogen, and energy source, water, and various ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how is cell density determined

A

colony counts on agar plates or by turbidity (spectrophotometry)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

chemoheterotroph

A

use organic compounds as both their energy source and their carbon source

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

exclusively uses respiration to meet its energy need

A

aerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

exclusively uses fermentation to meet its energy need

A

anaerobe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

faculative anaerobes

A

can respire or ferment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

microaerophilic

A

grow best at low O2 but can grow without O2 as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

which is more efficient fermentation or respiration?

A

respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

catalyzes the breakdown of H2O2 to H2O and O2

A

catalase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

is expressed by both prokaryotes and eukaryotes to help detoxify O2

A

SOD superoxide dismutase

17
Q

bacteria that lack SOD and catalase are most likely…..

A

anaerobic

because they are very sensitive to oxygen

18
Q

what extra enzyme do obligate aerobes have to protect themselves from oxygen

A

peroxidase

19
Q

bacteria can be identified based on their end products

A

fermentation

20
Q

in bacteria, folate is derived from…

A

para-aminobenzoic acid

21
Q

mammals, folate comes from…

A

diet

22
Q

folate is essential for the synthesis of ..

A

purines and thymidine

23
Q

what blocks dihydropteroate synthase DHPS (folate)

A

sulfonamides

24
Q

what blocks dihydrofolate reductase DHFR (folate)

A

DHFR inhibitor (trimethoprim)

25
Q

what do quinolones target?

A

Bacterial DNA gyrase required for unwinding/winding DNA

26
Q

what ribosomes do bacteria use

A

70S and 30S

27
Q

what do 70S ribosomes bind?

A

free 5’ end of mRNA as DNA is transcribed

28
Q

how are peptides within peptidoglycan cross-linked?

A

a peptide bond between the terminal D-Ala from one chain and a Lys (or other diamino amino acid) from other chain

29
Q

to which carbohydrate subunit is a peptide chain added in peptidoglycan?

A

NAM

30
Q

what five peptides are added to NAM?

A

L-ala D-glu L-lys D- ala D-ala

31
Q

Does the addition of a pentapeptide to UDP NAME require mRNA or ribosomes?

A

no

32
Q

List the steps of cell wall biosynthesis

A
  1. activation of carbohydrate subunits
  2. A pentapeptide is added to UDP-NAM
  3. UDP-NAM pentapeptide is attached to the bactoprenol through a pyrophosphate link with the release of UMP
  4. NAG is added to NAMpentapeptide bactoprenol complex
  5. the bactoprenol carrier transports the completed NAG-NAM pentapeptide repeat unit across the membrane to the outside
  6. The disaccharide unit is attached to the end of the growing peptidoglycan chain by enzymes call transglycosylases
  7. Pyrophosphobactoprenol is converted back to phosphobactoprenol and recycled
33
Q

between what amines does transpeptidation occur?

A

free amine of the diamino acid in the 3rd positiion of pentapeptide OR N-terminus of attached pentaglycine chain
AND
D-alanine at the 4th position of the other peptide chain

34
Q

what is released in transpeptidation?

A

D-alanine precursor

35
Q

what is another name for transpeptidases

A

penicillin binding proteins: because they are targets for penicillins and other beta-lactan antibiotics

Microbio Test I (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions