08.06 Endocrine signalling

Hormones bind to receptors on the cell membrane or inside target cells (if they can pass through the cell membrane), resulting in a change in the structure or function of the target tissue e.g. hormones can cause achange in growth or metabolism of cells. Refer also to sections 9.3 and 10.2. Only the correctly sized/shaped hormone (key) will bind to the specific receptor site (lock) to bring about a response or action. Ahormone will not activate a cell if it cannot bind to the receptors outside or inside the cell.

Figure 8.5 Hormones bind to specific receptors like a key fits into a lock