2.6 environmental control of metabolism Flashcards
Different types of microorganisms
Bacteria
Archaea
Eukaryotes
Microorganisms features
They have high adaptability
They are easy to cultivate
They have a fast growth speed.
Reason for using microorganisms
Some organisms can’t produce their own essential starting materials, so microorganisms produce these starting materials, so the other organisms can produce products that are essential for the other organisms survival
Examples of molecules produced by microorganisms
Amino acids
Vitamins
Fatty acids.
Growth media definition
Where an ideal environment is provided for microorganisms containing the raw materials and energy for the microorganisms to successfully grow.
Examples of growth media
Broth
Agar jelly
Broth
A liquid medium that allows microorganisms to grow, by providing energy and nutrients to the microorganisms.
Agar jelly
A solid medium that allows microorganisms to grow which has essential nutrient added to the jelly.
How do microorganisms gain energy
Chemical substances
Or light if photosynthetic
How is growth media used
To provide raw materials and energy to allow microorganisms to grow.
How is growth media used
To provide raw materials and energy to allow microorganisms to grow.
Examples of molecules produced by microorganisms
Vitamins
Fatty acids
Amino acids
Reasons to use micro organisms
To produce essential starting materials for organisms who cannot produce their own starting materials.
Fermenter definition
A container where microorganisms can grow in large quantities, which uses computers and probes to ensure optimum and desirable conditions for microorganisms are achieved.
Culture conditions (different methods of increasing microorganisms yield
Sterility
Temperature
Oxygen level
pH
Sterility
Killing off competitor microorganisms - reduces spoiling products and increases microorganisms success.
Temperature
Ensures that enzyme activity is at an optimum and therefore growth is at optimum.
Oxygen levels
Ensures microorganisms can undergo respiration at optimum rate.
pH
Ensure microorganisms conditions are acid/alkaline to suit them.
Growth curve
A graph which shows the number of microorganisms (log) and the time.
Phases of growth curves
Lag
Log
Stationary
Death
Lag phase
The graph stays flat
Little or no increase in cell number
Enzymes are induced to metabolise substrates
Log phase
Graph goes up
Cells grow and multiply at maximum rate providing no factors are limited.
Rapid growth due to plentiful nutrients.
New cells produced exceeds death rate.
Stationary phase
Graph goes flat
Nutrients in the culture become depleted or toxic metabolites are produced
Rate of new cells produced equals death rate.
Death phase
The graph goes down
Cells die due to a lack of nutrients or toxic metabolites accumulating
Death rate exceeds rate of new cells produced
Semi logarithmic scales
Used to show growth curves - with an x axis which is linear and a y axis which is logarithmic (goes up in powers)
Types of cell count
Total cell count
Viable cell count
