Following a meal, blood glucose concentration rises, triggering the secretion of insulin from the beta (β\betaβ) cells of the islets of Langerhans. Which of the following cellular responses is directly stimulated by the binding of insulin to its specific receptors on the membrane of target muscle cells?
Vesicles containing glucose transporter proteins fuse with the cell-surface membrane, increasing the rate of facilitated diffusion of glucose into the cytoplasm.
Adenylate cyclase is activated, leading to an increase in cyclic AMP (cAMP\text{cAMP}cAMP) concentration which initiates glycogenesis.
The enzyme glycogen phosphorylase is activated, increasing the rate of glycogenolysis to release free glucose.
Sodium-potassium pumps are inactivated to allow sodium-coupled active co-transport of glucose against its concentration gradient.
84 exam-style questions on OCR GCSE Biology 3.2 Coordination and control – the endocrine system, covering 3.2.1 Principles of hormonal coordination and control, 3.2.2 Roles of thyroxine and adrenaline, 3.2.3 Hormones in human reproduction, 3.2.4 Interactions of reproductive hormones, 3.2.5 Hormones in contraception, 3.2.6 Hormones in reproductive technologies, 3.2.7 Plant hormones in growth and coordination, 3.2.8 Effects of plant hormones, and 3.2.9 Uses of plant hormones. Each one has a worked solution and a mark scheme showing where the marks go.