genetic control of metabolism

Question 1

what is mutagenesis

Answer 1

the process of changing a microorganism’s genetic material using mutagenic agents (inducing mutation)

Question 2

give examples of mutagenic agents which can improve/change wild strains of DNA

Answer 2

radiation: gamma rays, UV light. Chemical: mustard gas, lead oxide

Question 3

what is recombinant DNA technology

Answer 3

involves the joining together of DNA from 2 different species. a technique to manipulate DNA within the laboratory and improve micro-organisms

Question 4

describe the role of vectors

Answer 4

carries section of DNA from the donor organism to the host cell. Examples of vectors include plasmids and artificial chromosomes.

Question 5

describe the role of restriction endonuclease enzyme

Answer 5

restriction endonuclease enzymes cut target sequences of DNA out of chromosomes, leaving sticky ends. using the same restriction endonuclease enzyme produces complementary sticky ends allowing the gene to be inserted into the plasmid

Question 6

describe the role of enzyme ligase

Answer 6

seals the gene into the plasmid

Question 7

describe the role of marker genes

Answer 7

a gene used to determine if a DNA sequence has been successfully inserted into a host organism’s DNA

Question 8

explain the use of required genes

Answer 8

gene inserted is used for whatever it produces e.g. insulin gene would be used to produce insulin

Question 9

why are recombinant yeast cells often used instead of bacteria

Answer 9

plant or animal recombinant DNA in bacteria can result in polypeptides that are folded incorrectly or lack post-translational modifications - this results in inactive proteins. these polypeptides can be produced more successfully in a recombinant yeast cell as they are eukaryotes and can undergo post-translational modification and fold correctly to form active proteins