Explain the benefits of making human therapeutic proteins, such as insulin, by recombinant DNA technology.
The two amino acid sequences shown in Fig. 3.1 can be compared. The amino acids that appear in the same position in both sequences can be counted and written as a percentage of the total number of amino acids in one sequence. This is known as the percentage sequence similarity. Use Fig. 3.1 to calculate the percentage sequence similarity of human and salmon calcitonin. Show your working.
Relative to human calcitonin, salmon calcitonin is more biologically active. It stays active in the human body for a longer period and binds to calcitonin receptors more readily. Bioinformatics was used to identify this more biologically active form of calcitonin for the treatment of osteoporosis. Explain how bioinformatics helped identify salmon calcitonin as a suitable form of calcitonin to treat human osteoporosis.
Use Fig. 3.1 to calculate the percentage sequence similarity of human and salmon calcitonin. Show your working.
Compared with human calcitonin, salmon calcitonin is more biologically active. It stays active in the human body for longer and binds to calcitonin receptors more readily. Bioinformatics was used to identify this more biologically active form of calcitonin for treating osteoporosis. Explain how bioinformatics helped identify salmon calcitonin as a suitable form of calcitonin to treat human osteoporosis.
Name an enzyme that can: • cut plasmid DNA • join the salmon calcitonin gene with plasmid DNA.
Identify and explain two properties of plasmids that let them be used as vectors in gene cloning.
The gene coding for salmon calcitonin is placed into bacteria in a specially designed plasmid known as an expression vector. An expression vector must include a prokaryotic promoter, such as the lac promoter. Explain why differences in the control of gene expression in prokaryotes and eukaryotes mean that expression vector plasmids must contain a prokaryotic promoter.