KA6 Enviromental Control Of Metabolism Flashcards
Why are microorganisms used in industries
Because of their adaptability speed of growth
Where are microorganisms grown
In large amounts in fermenters where certain conditions can be maintained
what is required to grow microorganisms in a fermenter
Growth median
Correct culture conditions
What is the 2 groups of a growth median
Raw materials for bio synthesis
Energy source
Explain raw materials for bionsynthesis in growth median
Microorganisms grown in a lab need liquid median eg agar in Petri dishes
Not all microorganisms have the same requirements
Some make complex molecules from simple ones
Some need complex compounds such as fatty acids or certain vitimins in the growth median
Explain energy source in growth median
Microorganisms need energy sources
Can come from chemical substances or a source of light in the case of photosynthesis
What are the 2 groups of correct culture conditions
Sterile conditions
Control of PH, temperture and oxygen levels
Explain sterile conditions for correct culture conditions
Sterile techniques used when working with microorganisms
Used to reduce the risk of contamination from other microorganisms
Why would contamination be a problem
Contaminated bacteria steals resources
Risk of spoilage of the products
Explain the control of PH, temperture and oxygen levels of correct culture conditions
These factors affect how well microbes grow in a lab
Temp- measured and controlled using sensors
Oxygen concentration- controlled by aeration
PH- controller using buffers or addition or acid
What are the phases of growth
The time taken for a cell to divide- generation/doubling time
A Lag phase
B log phase
C stationary phase
D death phase
Explain the lag phase
Enzymes are induced to metabolise substances
Explain the log phase
Rapid Peeiod of growth of microorganisms bcos lots of nutrients for the microorganisms
Explain the stationary phase
When the rate of the new cells is equal to the death rate
Occurs when nutrients run oiy and the production of toxic metabolites
Secondary metabolites ( antibiotics ) are produced
These give microorganisms ecological
Explain the death phase
When the toxic accumulation of metabolites or the lack of nutrients in the culture
Dying number of cells exceeds the number of new cells
