Genetic Control Of Metabolism Flashcards
What is mutagenesis?
What can it lead to?
- A process used to improve wild strains of micro-organisms by inducing mutations through exposure to uv light, radiation or chemicals.
- can lead to the development of improved strains that may have desirable traits.
What can be used to improve wild micro-organisms?
-Recombinant DNA technology
-Mutagenesis
True or False: All mutations produced by mutagenesis are beneficial.
False.
-While some mutations can lead to improved strains, others may be harmful or neutral.
What does recombinant DNA technology involve?
The use of recombinant plasmids and artificial chromosomes as vectors.
What is the role of restriction endonucleases in recombinant DNA technology?
They cut out specific genes from chromosomes, and then cut open plasmids, leaving sticky ends.
What is the role of ligase in recombinant DNA technology?
Seals the desired gene into the plasmid.
What are vectors in recombinant DNA technology?
DNA molecules used to carry foreign genetic information into another cell.
What types of vectors are used in recombinant DNA technology?
- Plasmids
- Artificial chromosomes
When are artificial chromosomes preferable to plasmids?
When larger fragments of foreign DNA are required to be inserted.
What are sticky ends?
Complementary ends produced when the same restriction endonuclease is used to cut open the plasmid and the gene.
What are restriction sites?
Target sequences of DNA where specific restriction endonucleases cut.
What do regulatory sequences control?
Gene expression of the vectors own gene and the inserted gene
What does the origin of replication allow?
Self replication of the plasmid/ artificial chromosome
What is recombinant dna technology? (1)
The manipulation of the genome of an organism by transferrring genes from one organism into a host micro-organism
What do recombinant plasmids and artificial chromosomes contain ? (4)
- restriction sites
- regulatory sequences
- origin of replication
- selectable markers
Why are safety mechanism genes introduced in micro-organisms?
To prevent the survival of the micro-organism in an external environment
Why are recombinant yeast cells sometimes used in protein production?
- They produce active forms of the protein which are inactive in bacteria
- plant or animal recombinant dna expressed in bacteria may result in polypeptides being incorrectly folded
What are selectable markers? What do they allow? (2)
-Antibiotic resistance genes that protect the micro-organism from selective agents ( antibiotics) that would normally kill it / prevent growing
- These markers allow for the identification of successfully transformed cells.
How do selectable marker genes function in vectors?
They ensure that only micro-organisms that have taken up the vector grow in the presence of the selective agent (antibiotic)
