2.6: Environmental Control of Metabolism Flashcards
What are the main micro-organisms?
Bacteria
Archaea
Eukaryotes
Why are micro-organisms used?
They are adaptable
Easy to cultivate
Grow quickly
What do micro-organisms use and produce?
They use a wide variety of substrates for metabolism
They produce a range of products from their metabolic pathways
Give examples of complex molecules required for biosynthesis.
Amino acids
Vitamins
Fatty acids
What do micro-organisms require?
Raw materials
Energy source
Give examples of complex molecule reactions
Amino acids –> protein
Sugars –> carbohydrates (starch, cellulose, glycogen)
Fatty acids + glycerol –> fats/lipids
Where is an energy source derived from?
Chemical substrates
Light in photosynthesis
What do sterile conditions do?
Reduce competition with desired micro-organisms for nutrients
Reduce the risk of spoilage of the product
What are the culture conditions?
Sterility
Control of temperature
Oxygen levels
pH
What are the phases of a bacteria growth chart thing
Lag phase
Log/exponential phase
Stationary phase
Death phase
Explain the Lag phase
Where enzymes are induced (give rise to) to metabolise substrates
Explain the Log/exponential phase
Contains the most rapid growth of micro-organisms due to plentiful nutrients
Explain the stationary phase
Occurs due to the nutrients in the culture media becoming depleted (used up) and the production of toxic metabolites
Explain the death phase
Occurs due to toxic accumulation of metabolites or the lack of nutrients in the culture
When are secondary metabolites produced
In the stationary phase
