Metabolism and survival: Key Area 6 - Environmental control of metabolism. Flashcards
There are three domains of life, what are they?
Bacteria, Archaea, Eukaryotes. (*prokaryotes)
Since micro-organisms can utilise a wide range of substrates for their metabolism, what do they produce a wide range of?
Useful substrates.
What does micro-organisms making a wide range of substrates make them ideal for?
Research and industrial use.
How can metabolism in micro organisms be altered?
manipulating their environmental conditions.
Wild strains may need to be improved, provide some examples.
- To improve gene stability
- To improve their ability to grow on low cost nutrients
- to produce larger quantities of target compound
- To allow easy harvesting of target compound after fermentation is complete.
What is Mutagenesis?
Mutagenesis is the creation of mutations
What is a mutation?
In nature mutations are rare and spontaneous and are the cause of variation.
What can the rate of mutations be increased by?
exposing organisms to mutagenic agents. eg. x-ray, radiation, mustard gas, colchicine
What does a mutant strain produced sometimes show?
Improved characteristics such as increased yield.
What could go wrong for mutant strains?
They’re often genetically unstable, and so many undergo reversed mutation (ie revert to the less useful wild-type state)
How do bacteria reproduce?
Asexually
Why do some strains of bacterial species arise?
Due to horizontal transfer of genetic material.
In horizontal gene transfer, what happens to plasmids or pieces of chromosomal DNA?
They are transferred from one gene to another.
How are new genes produced?
By bacteria taking up an incorporating DNA fragments from their surroundings.
