Genetic Control Of Metabolism Flashcards
What is a vector
A vector is a DNA molecule used to carry foreign genetic information into another cell and both plasmids and artificial chromosomes are used as vectors during recombinant DNA technology.
How can wild strains of microorganisms be improved?
• by mutagenesis
• recombinant DNA technology
Exposure to UV light…
And other forms of radiation or mutagenic chemicals results in mutations, some of which may produce an improved strain of micro organism
What does recombinant DNA technology involve?
Recombinant DNA technology involves the use of recombinant plasmids and artificial chromosomes as vectors.
What are artificial chromosomes preferable to?
Preferable to plasmids as vectors when larger fragments of foreign DNA are required to be inserted.
What do restriction endonuclease do?
Restriction endonuclease cut open plasmids and specific genes out of chromosomes, leaving sticky ends.
When are complementary sticky ends produced?
When the same restriction endonuclease is used to cut open the plasmid and the gene from the chromosome.
What does ligase do?
Seals the gene into the plasmid
What do recombinant plasmids and artificial chromosomes contain?
• Restriction sites
• regulatory sequences
• origin of replication
• selectable markers
What do restriction sites contain?
Restriction sites contain target sequences of DNA where specific restriction endonuclease cut.
What do regulatory sequences control?
Gene expression and origin of replication allows self replication of the plasmid/artificial chromosome.
Selectable markers…
Such as antibiotic resistance genes protect the micro organism from a selective agent (antibiotic) that would normally kill it or prevent growth.
What do selectable marker genes which are present in the vector ensure?
Ensure that only micro organisms that have taken up the vector grow in the presence of the selective agent (antibiotic).
As a safety mechanism…
Genes are often introduced that prevent the survival of the micro organism in an external environment.
Use of recombinant yeast cells…
To produce active forms of the protein which are inactive in bacteria.
