Describe how the liver lowers blood glucose concentration after insulin has been secreted.
Nearly all insulin used to treat type I diabetes is manufactured by genetically engineered bacteria or yeast. Figure 4.1 summarises this method.
One approach for step 1 is to take mRNA from $\beta$ 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 $\beta$ cell is easier than isolating the DNA for insulin in a $\beta$ cell.
Outline how restriction enzymes are used in step 2.
Most people with type I diabetes inject insulin. A recent product contains insulin that can be given through a nasal spray. The spray is inhaled and the insulin is absorbed through the lungs. Fig. 4.2 shows the concentration of insulin in blood plasma in the 480 minutes after insulin is injected or inhaled. In both cases, the insulin was the same type, produced by genetically engineered $\textit{Escherichia coli}$. Fig. 4.3 shows the concentration of glucose in blood plasma in the 480 minutes after insulin is injected or inhaled.
Compare the findings for injected insulin and inhaled insulin shown in Fig. 4.2.
Using Fig. 4.2, explain the differences in the blood glucose levels after insulin is injected or inhaled as shown in Fig. 4.3.
Using Figs. 4.2 and 4.3, suggest one advantage and one disadvantage of inhaling insulin instead of injecting it.
Compare the findings for injected insulin and inhaled insulin shown in Fig. 4.3.
Using Fig. 4.2, explain the differences in the blood glucose levels after insulin is injected or inhaled as shown in Fig. 4.3.
Using Figs. 4.2 and 4.3, suggest one advantage and one disadvantage of inhaling insulin rather than injecting it.