Genetic Control of Metabolism Flashcards
(12 cards)
How can wild strains of micro-organisms be improved
Through mutagenesis or recombinant DNA technology. Exposure to UV light, radiation or mutagenic chemcials may result in mutations which may produce an improved strain.
What does recombinant DNA technology involve
It involves the use of recombinant plasmids and artificial chromosomes as vectors.
What is a vector
A DNA molecule used to carry foreign genetic information into another cell. Both plasmids and artificial chromosomes are used but artifical chromosomes are preferred when larger fragments of DNA are to be inserted.
What are 4 things that recombinant plasmids and artificial chromosomes contain
Restriction sites, regulatory sequences, origin of replication and selectable markers
What is the role of restrictive endonucleases and ligase in recombinant DNA technology
Restriction endonucleases cut open plasmids and specific genes out of chromosomes, leaving sticky ends.
Complementary sticky ends are produced when the same restriction endonuclease is used to cut open the plasmid and the gene from the chromosome. Ligase seals the gene into the plasmid.
What do restriction sites contain?
They contain target sequences of DNA where specific restriction endonucleuses cut.
What do regulatory sequences
They control gene expression
What do selectable markers do
Markers such as antibiotic resistance genes protect the micro-organism from a selective agent (antibiotic) that would kill it or prevent growth. They present in the vector to ensure that only the micro-organisms that have taken up the vector grow in the prescence of the selective agent
what does origin of replication do
Allows self-replication of the plasmid/artificial chromosome
What can recombinant yeast cells be used for and why
To produce active forms of proteins that are innactive in bacteria. This is because yeast cells often have the cellular machinery required for proper protein folding that is not found in bacterial cells.
Name one safety measure taken when culturing micro-organisms
Genes are introduced to the micro-organism that prevent it’s survival in an external environment
Why can’t recombinant plant or animal cells be used instead of yeast.
Plant or animal recombinant DNA expressed in bacteria may result in polypeptides being incorrectly folded
