AP BIOLOGY

Detailed explanation-1: -Signal transduction pathways, which control the response of cells to various environmental signals, are mediated by the function of signaling proteins that interact with each other and activate one other with high specificity.

Detailed explanation-2: -2. Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way. This change initiates the process of transduction. Signal transduction is usually a pathway of several steps.

Detailed explanation-3: -Even though cells have identical receptors, cells are able to respond in different ways because they have types of machinery internally capable of coupling. They can respond differently because they are able to elicit different effector proteins in the pathways.

Detailed explanation-4: -Cell-surface receptors come in three main types: ion channel receptors, GPCRs, and enzyme-linked receptors. When a ligand binds an ion channel receptor, a channel through the plasma membrane opens that allows specific ions to pass through.