Unit 2 Enviromental Control Of Metabolism

Question 1

What are three key groups that microorganism species are from?

Answer 1

Archaea
Bacteria
Eukaryotes

Question 2

List five reasons where micro organisms are useful in research and industrial applications?

Answer 2

They reproduce and grow quickly
They are easy to cultivate
Their Food substrate is cheap
Their metabolism are easy to manipulate
They produce many useful products

Question 3

What two things influence the growth of a micro organism?

Answer 3

Composition of growth medium

Environmental conditions

Question 4

What two things do we always need to provide when culturing micro organisms?

Answer 4

Energy source

Raw materials for biosynthesis

Question 5

Define biosynthesis?

Answer 5

The use of raw materials to make more complex molecules

Question 6

State when micro organism will need to use oxygen?

Answer 6

Oxygen

Component of many organic materials, final electron exceptor

Question 7

State when micro organisms need to use nitrogen?

Answer 7

Nitrogen

Synthesis of amino acids, nucleic acids and proteins

Question 8

State When micro organisms need to use phosphorus?

Answer 8

Phosphorus

Synthesis of ATP, nucleic acids

Question 9

Stay when Micro organisms need sulfur?

Answer 9

Sulfur

Synthesis of amino acids

Question 10

Why do fermenters need a cooling jacket/sleeve?

Answer 10

To keep temperature inside the fermenter constant And at an optimum

Question 11

Why does the fermenter need impellers?

Answer 11

Stirring a mixing the micro organisms and the nutrients and distributing the heat

Question 12

Why are fermenters made of stainless steel?

Answer 12

As it’s easy to keep clean and sterile and there is no corrosion

Question 13

List two sources of energy that could be used to supply micro organisms in a fermenter:

Answer 13

Chemical compounds

Light

Question 14

List three abiotic factors that might need to be controlled and monitored in an industrial fermenter:

Answer 14

Temperature
pH
Oxygen levels

Question 15

Explain why it’s important to maintain sterile conditions within a fermenter?

Answer 15

So that it would reduce competition of nutrients

Reduces risk of spoilage of product

Question 16

Define growth:

Answer 16

Growth is the Irreversible increase in dry biomass of an organism

Question 17

How do we measure growth of a micro organism?

Answer 17

Measuring increase in cell number over a period of time

Question 18

What is the lag phase?

Answer 18

The lag phase is where there is little to no increase in cell number
Cells adjust to the growth medium and produce enzymes
They have a primary metabolism so primary metabolites are obtained for biosynthesis

Question 19

What is the log/exponential phase?

Answer 19

Cells multiply at a maximum rate provided the nutrients plentiful and have no limiting factor
Steep incline and graphs as population doubles with each cell division

Question 20

What is the stationary phase?

Answer 20

The stationary phase is when the number of cells produced equals the number of cells dying
Due to the depletion of culture/buildup of toxic metabolites
Secondary metabolism which produces the products

Question 21

What is the death phase?

Answer 21

The number of cells dying is greater than that are being produced

Question 22

What type of scale is used for the Y axis of the graph?

Answer 22

Logarithmic scale/Log scale

Question 23

What do we use cell counts for when culturing microorganisms in fermenters?

Answer 23

To estimate population size

Question 24

What is total cell count?

Answer 24

Total cell count is counting all viable and dead cells

Question 25

What is viable cell count and what does it show us?

Answer 25

Counting only living microorganisms

Can show a death face if there is one