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In the 1970s, recombinant deoxyribonucleic acid methods for cloning and expressing genes in the bacteria *Escherichia coli* were under intense development - VCE - SSCE Biology - Question 10 - 2021 - Paper 1
Question 10
In the 1970s, recombinant deoxyribonucleic acid methods for cloning and expressing genes in the bacteria *Escherichia coli* were under intense development. An import... show full transcript
Worked Solution & Example Answer:In the 1970s, recombinant deoxyribonucleic acid methods for cloning and expressing genes in the bacteria *Escherichia coli* were under intense development - VCE - SSCE Biology - Question 10 - 2021 - Paper 1
Step 1
What is meant by recombinant deoxyribonucleic acid in the context of this article?
Answer
Recombinant deoxyribonucleic acid (DNA) refers to DNA molecules that have been artificially created by combining genetic material from different sources. In the context of this article, it is the method used to clone and express genes, such as the human insulin gene, within a bacterial host. This technology allows the manipulation of genetic sequences to produce desired proteins, making it essential in biotechnology and medicine.
Step 2
How did the researchers use this information to genetically engineer a human insulin gene from the recombinant human insulin in the laboratory?
Answer
The researchers used the known amino acid sequence of human insulin to deduce the corresponding mRNA and DNA sequences. By working backwards from the amino acid sequence, they could identify the possible nucleotides needed. They synthesized the human insulin gene based on this information or isolated it from human DNA. They then inserted the insulin gene into plasmids to create recombinant DNA, which was then introduced into E. coli bacteria for expression.
Step 3
Describe the steps to clone and express the gene in bacteria.
Answer
- Isolate human insulin gene from human or artificially synthesise the human insulin gene from the known sequence.
- Insert the insulin gene into a plasmid using restriction enzymes to cut and ligate the pieces together to form the recombinant plasmid.
- Introduce the recombinant plasmid into bacteria. These bacteria are then grown in culture.