In the endocrine regulation of blood glucose, the hormones adrenaline and glucagon coordinate glycogen breakdown in hepatocytes via a second messenger pathway. Which of the following correctly describes the sequence of molecular events during this process?
The hormone binds to a specific cell-surface receptor, activating adenylate cyclase. This enzyme converts ATP to cyclic AMP (cAMP), which acts as a second messenger to activate protein kinase, leading to glycogen hydrolysis.
The hormone binds to a specific cell-surface receptor, activating protein kinase. Protein kinase converts ATP to cyclic AMP (cAMP), which acts as a second messenger to activate adenylate cyclase, leading to glycogen hydrolysis.
The lipid-soluble hormone crosses the cell membrane and binds to an intracellular receptor, activating adenylate cyclase. This enzyme converts cyclic AMP (cAMP) to ATP, which directly phosphorylates glycogen to release glucose.
The hormone binds to a specific cell-surface receptor, activating adenylate cyclase. This enzyme converts cyclic AMP (cAMP) to ATP, which acts as a second messenger to activate protein kinase, leading to glycogen hydrolysis.
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.