Bacterial Growth

Question 1

Mean residence time (MRT)

Answer 1

How long bacteria stays in the vessel before it is flushed out

Question 2

MRT

Answer 2

V/F

Question 3

F

Answer 3

Flow rate in chemostat

Question 4

Dilution rate

Answer 4

1/MRT

D = mu - specific growth rate constant

Question 5

Steady state

Answer 5

The steady state in a chemostat occurs when the growth rate of microorganisms equals the dilution rate of the medium

Question 6

What makes up most of RNA in cells?

Answer 6

tRNA + rRNA

RNA increases as growth rate increases

Question 7

Why does RNA increase as growth rate increases?

Answer 7

More protein synthesising systems needed e.g. ribosomes made up of RNA

Ribosome number increases

Question 8

Change in macromolecular composition

Answer 8

Nutrition mediate but not nutrition specific

Question 9

Ribosomes in response to growth rate

Answer 9

Constnat rate of protein synthesis - doesn’t change with environmental conditions

More ribosomes made in response to increasing growth rate

Question 10

Nutrient Up-Shift

Answer 10

Glucose minimum medium -> nutrient broth rich environment

Doublings increase in response after ribosome synthesis

Question 11

Nutrient Down-shift

Answer 11

Broth –> glucose minimal medium

Extended lag period and slower rate of increase
far more ribosomes than it needs

inverse of upshift