Lecture 28: Microbial population growth

Question 1

smaller organisms can grow…

Answer 1

faster

Question 2

binary fission is…

Answer 2

the process by which microorganism can replicate themselves

Question 3

prokaryotes reproduce…

Answer 3

asexually

Question 4

the process by which prokaryotes reproduce is…

Answer 4

binary fission

Question 5

binary fission results in the formation of

Answer 5

two cells that are genetically identical

Question 6

step 1 of binary fission:

Answer 6

chromosome replication begins

Question 7

step 2 of binary fission:

Answer 7

one copy of the origin moves to each end of the cell

Question 8

step 3 of binary fission:

Answer 8

replication finishes

Question 9

step 4 of binary fission:

Answer 9

two daughter cells result

Question 10

closed batch culture system refers to

Answer 10

a form of cell culturing

Question 11

closed batch culture systems have a defined

Answer 11

supply of nutrients

Question 12

once nutrients in a system have been used cells cannot

Answer 12

proliferate

Question 13

what is the “lag phase” of microbial growth in a closed batch culture system

Answer 13

the time required to get biosynthetic reactions occurring

Question 14

what is the “exponential phase (log phase)” of microbial growth in a closed batch culture system

Answer 14

• where cells are actively dividing and nothing is limiting growth
• population is doubling

Question 15

what is the “stationary phase” of microbial growth in a closed batch culture system

Answer 15

• cells stop growing and cryptic growth is observed

Question 16

cryptic growth is

Answer 16

when organisms survive by consuming lysed cell constituents of other dead cells within the culture

Question 17

in the stationary phase the population is

Answer 17

dynamic

Question 18

dynamic population means

Answer 18

there is an equilibrium between growing and dying cells

Question 19

what is the “death phase” of microbial growth in a closed batch culture system

Answer 19

equilibrium between growing cells and dying cells is skewed towards death

Question 20

growth rate is

Answer 20

a measure of the average to see what the population is doing

Question 21

persisters are

Answer 21

insensitive to penicillin because they are dormant

Question 22

penicillin stops bacteria by

Answer 22

preventing the cell wall forming meaning it falls apart during replication

Question 23

three requirements for prokaryote growth

Answer 23

• carbon source
• energy source
• reducing power

Question 24

carbon source for prokaryote growth is used as

Answer 24

building blocks for macromolecular synthesis

Question 25

the energy source for prokaryote growth is used for

Answer 25

anabolic and catabolic reactions in the cell

Question 26

reducing power is required for prokaryote growth to

Answer 26

carry energy/electrons

Question 27

photoautotrophs | energy/carbon source

Answer 27

energy source = light | carbon source = harvest their own

Question 28

chemoautotrophs

Answer 28

energy source = chemical compounds | carbon source = harvest their own

Question 29

photoheterotrphs

Answer 29

energy source = light | carbon source = harvest carbon from other molecules

Question 30

chemoheterotrophs

Answer 30

energy source = chemical compounds | carbon source = harvest their own from other molecules