Genetic Technology

Question 1

How is insulin produced?

Answer 1

1. There were problems in locating and isolating the gene coding for human insulin from all the rest of the DNA in a human cell
2. Instead of cutting out the gene from the DNA in the relevant chromosome, they extracted mRNA for insulin from pancreatic Beta cells which are the only cells to express the insulin gene
3. These cells contain large quantities of mRNA for insulin as they are its only source in the body

Question 2

What happens to mRNA in insulin production?

Answer 2

1. The mRNA was then incubated with the enzyme reverse transcriptase which comes from retroviruses
2. This enzyme reverses transcription using mRNA as a template to make single stranded DNA
3. These single stranded DNA molecules were then converted to double stranded DNA molecules using DNA polymerase to assemble nucleotides to make the complimentary strand
4. Now genetic engineers had insulin genes they could insert into plasmids to transform the bacterium Escherichia coli.

Question 3

What is the advantage of this form of insulin?

Answer 3

• Now a reliable supply available to meet increasing demand

- Supplies are not dependent on factors such as availability through the meat trade