Chemical control in mammalsEdexcel A-Level Biology B: Mind map

Exam questions on Chemical control in mammals

1. The adrenal glands, the thyroid gland and the pancreas are endocrine glands. A hormone released from an adrenal gland is carried in the blood to every tissue in the body, but only some tissues respond to it.
   Explain why adrenaline causes a response in liver cells but not in every cell it reaches.2 marks
2. Adrenaline is secreted by the adrenal glands during a stress response. In a liver cell, adrenaline binds to a receptor on the cell surface membrane. This activates an enzyme, adenylyl cyclase, which converts ATP to cyclic AMP (cAMP). The cAMP then activates other enzymes in the cell, which break down glycogen to glucose.
   Explain how the use of a second messenger allows a small amount of adrenaline to cause a large response.2 marks
3. Oestrogen is a steroid hormone secreted by the ovaries. It is lipid-soluble. It stimulates cells in the lining of the uterus to grow and to produce new proteins.
   Describe how oestrogen causes a target cell to produce a new protein.3 marks