Question

Short / Long answer type questions.
In one type of diabetes the plasma concentration of the hormone insulin is normal but the response of the cells to which insulin usually binds is markedly decreased. Suggest a reason for this observation in terms of the properties of protein binding sites.

Answer 1

This is a case of type 2 diabetes mellitus. In this condition response of the cells to which insulin usually binds is markedly decreased because of non-responsiveness of insulin receptors. The activity of activation of the insulin receptor is inducing glucose uptake. For this reason "insulin insensitivity", or a decrease in insulin receptor signalling, leads to diabetes mellitus type 2 – the cells are unable to take up glucose, and the result is hyperglycemia (an increase in circulating glucose), and other conditions associated with diabetes. A high intake of dietary fat causes lipid overload and insulin resistance in the muscle and liver, which are the main sites where insulin receptors are found.