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a. Outline how human insulin is made using recombinant plasmids - VCE - SSCE Biology - Question 6 - 2023 - Paper 1
Question 6
a. Outline how human insulin is made using recombinant plasmids. There are different types of insulin available for use. The activity profile of each of these insul... show full transcript
Worked Solution & Example Answer:a. Outline how human insulin is made using recombinant plasmids - VCE - SSCE Biology - Question 6 - 2023 - Paper 1
Step 1
Outline how human insulin is made using recombinant plasmids.
Answer
To produce human insulin using recombinant plasmids, the following steps are generally followed:
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Gene Isolation: The genes coding for insulin chains A and B are isolated from human DNA.
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Plasmid Preparation: A plasmid vector is prepared by using restriction endonucleases to cut it open, allowing for the insertion of the insulin genes.
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Insertion: The insulin genes are inserted into the plasmid. DNA ligase is used to join the DNA fragments.
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Transformation: The recombinant plasmids are introduced into bacterial cells, which transform with the plasmid and start to express the insulin genes.
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Selection: Antibiotic selection is used to identify successfully transformed bacteria that carry the insulin plasmids.
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Protein Processing: The bacteria are induced to produce the insulin chains, which are then processed together to form functional human insulin. This involves joining the two polypeptide chains via disulfide bridges.
Step 2
Identify which type of insulin is rapid acting compared to regular insulin. Use data from the graph to justify your response.
Answer
The rapid-acting insulin compared to regular insulin is lispro. According to the graph, lispro peaks quickly at around 2 hours, achieving a relative insulin activity of approximately 6 arbitrary units, whereas regular insulin peaks at about 5 hours with a peak activity of 5 arbitrary units. This implies that lispro has a shorter onset and peak duration compared to regular insulin.
Step 3
Step 4
What should scientists consider when altering the primary structure of insulin? Justify your response.
Answer
Scientists should consider the tertiary structure of insulin when altering its primary structure. Changes in the primary structure, which is the sequence of amino acids, can lead to alterations in the overall folding and functionality of the insulin molecule. Proper folding is essential for insulin's biological activity, so any modifications must ensure that the resulting structure remains functional.