Microbial Population Growth

Question 1

What domains are microorganisms found in?

Answer 1

All 3 domains but primarily within the prokaryotes (bacteria and archaea)

Question 2

what is the dominant life form?

Answer 2

Prokaryotes

Question 3

How many bacterial cells estimated to be on earth?

Answer 3

5x10^30

Question 4

What is most life?

Answer 4

Microbial

Question 5

Are microorganism pathogenic?

Answer 5

Only a very small fraction

Question 6

Why are prokaryotes so dominant?

Answer 6

Because they are small which means they have a fast growth rate and can therefore evolve and adapt fast

Question 7

What is binary fission?

Answer 7

The cell division process which prokaryotes use to reproduce asexually. 1 cell to 2

Question 8

What is the result of binary fission?

Answer 8

Two cells that are genetically identical

Question 9

What is the first step of binary fission?

Answer 9

Chromosome replication begins

Question 10

What happens after chromosome replication begins?

Answer 10

One copy of the origin is now at each end of the cell

Question 11

What happens once one copy of the origin is at each end of the cell?

Answer 11

Replication finishes

Question 12

What does closed batch culture system refer to?

Answer 12

A form of cell culturing

Question 13

What is within a closed batch culture system?

Answer 13

There is a defined amount of nutrient supply provided and once used, the cells can’t multiply (there is no in flow or out flow of nutrients)

Question 14

what is closed batch culture system?

Answer 14

The standard method of studying microorganisms in culture

Question 15

What is closed batch culture system dictated by?

Answer 15

The method, not the shape of the flask

Question 16

What is the lag phase?

Answer 16

The time between when an organism is first put in the conditions to when biosynthetic reactions begin (growth starts)

Question 17

What does the length of the lag phase depend on?

Answer 17

The history of the organism (whether it has come from same, similar or different conditions)

Question 18

What is the exponential phase?

Answer 18

When cells are actively dividing and nothing is limiting for growth. Population will double in a constant time interval under standard conditions

Question 19

What is stationary phase?

Answer 19

When cells stop growing and cryptic growth is observed

Question 20

What is cryptic growth?

Answer 20

When organisms survive by consuming lysed cell constituents of other dead cells within the culture. It is not a static population but a dynamic population

Question 21

What is meant by a dynamic population?

Answer 21

There is an equilibrium between the death rate and growth rate

Question 22

What is death phase?

Answer 22

Cell death. Equilibrium between growing cells and dying cells is skewed to the dead

Question 23

What does batch culture analysis measure?

Answer 23

The average behaviour of cells

Question 24

What is penicillin?

Answer 24

An antibiotic which kills bacteria by blocking cell wall synthesis, only growing/replicating bacteria are affected

Question 25

Why are persisters insensitive to penicillin?

Answer 25

because they are in a dormant, non-dividing phase, similar to that of bacteria in the lag phase of the growth curve, and because penicillin kills bacteria only when they are dividing or about to divide

Question 26

What do prokaryotes need to multiply?

Answer 26

Carbon source, energy source and reducing power

Question 27

What is carbon source?

Answer 27

Building blocks needed for macromolecular synthesis

Question 28

What is energy source?

Answer 28

(Electrons) to drive anabolic and catabolic reactions in a cell

Question 29

What is reducing power?

Answer 29

Carriers of energy/electrons (NAD+/NADP+) for transferring energy

Question 30

How do prokaryotes harvest energy?

Answer 30

From chemical energy stored in bonds. Broken chemical bonds release energy that can be captured in new bonds (ATP)

Question 31

What is the most common energy currency?

Answer 31

ATP

Question 32

What can be done with ATP bonds formed?

Answer 32

The can be broken again later to release the energy

Question 33

What is catabolism?

Answer 33

Energy generation "energy/building block harvesting"

Question 34

What happens during catabolism?

Answer 34

The breakdown of food into products

Question 35

What is anabolism?

Answer 35

Energy consumption "energy/building block use"

Question 36

What happens during anabolism?

Answer 36

Monomers are built up into macromolecules and other cellular constituents

Question 37

What is the two possible energy sources?

Answer 37

Chemical compounds and light

Question 38

What is the prefix if the energy source is light?

Answer 38

Photo-

Question 39

What is the prefix if the energy source is chemical compounds?

Answer 39

Chemo-

Question 40

What are the two possible carbon sources?

Answer 40

Carbon dioxide and organic compounds

Question 41

What is the prefix if the carbon source is carbon dioxide?

Answer 41

Auto-

Question 42

What is the prefix if the carbon source is organic compounds?

Answer 42

Hetero-

Question 43

What processes may chemoheterotrophs undergo?

Answer 43

aerobic respiration, anaerobic respiration or fermentation to get energy