U2 KA6 Flashcards
1
Q
Why are microorganisms used in research? (3)
A
- they can be easily cultured.
- have a fast growth rate.
- easily adaptable.
2
Q
What domain of life contains microorganisms?
A
- all 3, (Archea, Bacteria, Eukaryotes)
3
Q
What is a growth medium?
A
- a sterile solution created to support growth of microorganisms, containing required nutrients.
4
Q
What conditions are required for culturing?
A
- a sterile environment.
- control of; pH, temp, O2 levels.
5
Q
What is a viable cell count?
A
- the number of actively dividing cells in a sample.
6
Q
What is the total cell count?
A
- the number of living or dead cells in a giving volume.
7
Q
What occurs in the Log (exponential) phase?
A
- microbes multiply at a rapid rate.
7
Q
What occurs in the Lag phase?
A
- no change in cell number, however they have high metabolic activity as they adjust to the mediums growth conditions.
- the microorganisms do not divide until enzymes are induced.
8
Q
What occurs in the stationary phase?
A
- the number of microbes produced = the number of microbes dying.
- toxic metabolites are produced and the growth medium is depleted.
9
Q
What occurs in the death phase?
A
- microbes die due to increase in toxic metabolites as the medium lacks nutrients to support them.
10
Q
What is the role of the secondary metabolite?
A
- it gives an ecological advantages as it allows it to outcompetes other bacteria.
