Describe how the liver lowers blood glucose concentration after insulin is secreted.
Almost all insulin used to treat type I diabetes comes from genetically engineered bacteria or yeast. Fig. 4.1 summarises this process.
One method for step 1 is to collect mRNA from β cells in the pancreas. The relevant mRNA is then isolated and used to make DNA. Suggest why isolating the mRNA coding for insulin in a β cell is easier than isolating the DNA for insulin in a β cell.
Outline how restriction enzymes are used in step 2.
Most people with type I diabetes inject insulin. A newer product uses insulin delivered by nasal spray. The spray is inhaled and the insulin is absorbed through the lungs. Fig. 4.2 shows the concentration of insulin in the blood plasma in the $480$ minutes after injecting or inhaling insulin. In both cases, the insulin was the same type, obtained from genetically engineered Escherichia coli. Fig. 4.3 shows the concentration of glucose in the blood plasma in the $480$ minutes after injecting or inhaling insulin.
Compare the results for injected insulin and inhaled insulin shown in Fig. 4.2.
With reference to Fig. 4.2, explain why the blood glucose levels after injecting or inhaling insulin differ in Fig. 4.3.
With reference to Figs. 4.2 and 4.3, suggest one advantage and one disadvantage of inhaling insulin rather than injecting it. Give one advantage and one disadvantage.
Compare the results for injected insulin and inhaled insulin shown in Fig. 4.3.
With reference to Fig. 4.2, explain why the blood glucose levels after injecting or inhaling insulin differ in Fig. 4.3.
With reference to Figs. 4.2 and 4.3, suggest one advantage and one disadvantage of inhaling insulin rather than injecting it.