U2 KA7 Flashcards
1
Q
What 2 ways can wild strains of micro-organisms be improved?
A
- mutagenesis.
- Recombinant DNA technology.
2
Q
What is Mutagenesis?
A
- a process by which an organisms DNA is altered by causing a gene mutation.
3
Q
What is a Mutagenic Agent?
A
- a chemical or agent capable of inducing mutagenic changes.
- eg. Chemicals/Radiation.
4
Q
What is a vector?
A
- a DNA molecule used to carry foreign genetic info to another cell.
- eg. Recombinant Plasmids.
5
Q
What is the role of Restriction Endonuclease? (2)
A
- to recognise and cut desired DNA sequences into fragments.
- to cut open plasmids and leave sticky ends.
6
Q
What is the role of Ligase?
A
- to seal the gene into to plasmid.
7
Q
What is a restriction site?
A
- a target sequence of DNA which specific restriction endonuclease cut.
8
Q
What is the role of regulatory sequences?
A
- to control gene expression.
9
Q
Why are selectable markers used?
A
- so that only microorganisms that have received the vector will replicate when the selective agent is added.
10
Q
What is the safety mechanism required for Recombinant DNA technology?
A
- certain genes must be added to prevent the survival of microorganisms in an external environment.
11
Q
Why are recombinant yeast cells used?
A
- to produce active forms of proteins that are inactive in bacteria.
12
Q
When are artificial chromosomes used instead of plasmids?
A
- if the target sequence is very large.
13
Q
What are the stages of Recombinant DNA technology?
A
- a certain gene is targeted.
- restriction endonuclease
cut the DNA into fragments with sticky ends. - the same restriction endonuclease is used to cut open the plasmid, leaving complimentary sticky ends.
- Ligase seals the gene into the plasmid.
14
Q
Why do bacteria produce inactive proteins?
A
- the polypeptide is folded incorrectly.
