2.6 Environmental Control of metabolism Flashcards
What is a microorganism
A microscopic organism which may exist in a single celled form or a colony of cells
Name 3 examples of a microorganism
Archaea, bacteria and some eukaryotes
Why are microorganisms used by scientists
Their adaptability, ease of cultivation and speed of growth
What is cell culture
Cell culture is the process by which cells are grown under controlled conditions, generally outside their natural environment
What is cell growth influenced by
Growth medium and environmental factors
What is a growth medium
Is a solid, liquid or semi-solid designed to support the growth of a population of microorganisms
What do many microorganisms produce `
The complex molecules requires for biosynthesis
What are energy sources derived from
Chemical substrates or light in photosynthetic microorganisms
What can cells be cultured in?
Petri dish, flask or fermenter
Name 4 culture conditions
Sterility, temperature, oxygen levels and pH
Why must fermenters be sterile?
It reduces competition with desired microorganisms for nutrients and reduce the risk of spoilage of the product
Why are temperature and pH important culture conditions?
For optimum enzyme activity
What are the 4 phases of growth in a microorganism, in order
Lag, Log, Stationary and Death
What happens during the lag phase
There is no increase in cell number and enzymes are induced
What happens during the log phase
Contains the most rapid growth of microorganisms due to plentiful nutrients
