Microbiology Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

flagellum function

A

for motility

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

pili

A

for attaching to surfaces and transferring plasmids by conjugation

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

plasmid

A

circular DNA which contains extra bacterial genes including genes for antibiotic resistance

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

where is the circular DNAs of prokaryotes found

A

in the nucleoid

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

by which process do prokaryotes reproduce

A

binary fission

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

the main function of the cell wall
other functions of the cell wall

A

*To prevent osmotic lysis
it supports the structure of the cell and provides rigidity to the cell
provides pressure inside the cell

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

what is a bacterial cell wall made of

A

peptidoglycan

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

what antibiotic is used instead of penicillin to combat gram-negative bacteria

A

vancomycin

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

physical requirements in which microbes thrive

A

optimal ph
optimal temperature
aerobic environments for some microbes

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

the optimal temperature for pathogens to grow(mesophiles)

A

37 degrees

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

at what temperature should bacteria be incubated, and for how long?

A

at 25 degrees and between 24-48 hours

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

which do we not completely seal the plate containing

A

to allow oxygen into the plate

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

why do we incubate bacteria at 25 degrees, and not completely seal the plate containing bacteria?

A

to ensure that the growth of pathogenic bacteria is low, as bacteria tend to grow rapidly at body temperature (37 degrees) and in anaerobic conditions

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

obligate aerobes

A

bacteria that require oxygen to replicate

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

obligate anaerobes

A

bacteria that can only survive and replicate in the absence of oxygen

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

facultative anaerobes

A

bacteria that are able to survive in the absence of oxygen but grow and divide faster in the presence of oxygen

17
Q

in which two mediums can bacteria be grown

A

on liquid media like broth
on solid media containing agar

18
Q

bacterium growth media usually contain a carbon source and a nitrogen source. true or false

A

true

19
Q

in which form is the carbon source in a media usually in

A

in the form of glucose

20
Q

the purposes of aseptic techniques

A

to prevent contamination of the environment by the microbes being handled

to prevent contamination of the microbial cultures by unwanted microbes from the environment

21
Q

what are the purposes of the following aseptic techniques
1. Autoclaving all glassware at 121 degrees for 15 minutes
2. flaming loops and wires until red hot.
3. opening the petri dish lids at a small angle
4. roaring blue flame
5. keeping McCartney caps in hand and flaming the neck of the bottle

A
  1. kill bacteria and spores
  2. To kill bacteria
  3. to prevent bacteria from entering the dish
  4. to create a convection current to uplift air away from the cultures
  5. to not contaminate the desk and also to create a convection current to lift air from the broth
22
Q

purpose of sterilizing materials during experiments

A

to grow pure cultures of microorganisms

23
Q

how do we sterilize plastics like Petri dishes

A

by irradiating them

24
Q

how do we sterilize the growth media

A

by heating it in an autoclave

25
Q

autoclave

A

a pressure cooker that allows a pressure of 15 atm and a temperature of 121 degrees to be generated

26
Q

the function of streak plates

A

can be used to separate mixed cultures into pure ones by separating out individual colonies which can then be used to inoculate fresh plates

27
Q

to inoculate means

A

to introduce cells or organisms into a culture medium

28
Q

state three problems encountered when trying to count bacteria(what are the solutions to these problems)

A

they are small (use a microscope or spread them onto agar and allow them to grow into a colony)
they are several of them (Dilute the sample)
it is difficult to determine whether they are alive or dead (allow them to grow into colonies)