AP BIOLOGY

Detailed explanation-1: -Answer and Explanation: Binding of a signal molecule to an ligand gated ion channel will lead to the change in the distribution of ions when opposite sides of a membrane.

Detailed explanation-2: -Signaling molecules bind to the extracellular domain of two nearby tyrosine kinase receptors, which then dimerize. Phosphates are then added to tyrosine residues on the intracellular domain of the receptors and can then transmit the signal to the next messenger within the cytoplasm.

Detailed explanation-3: -Signal molecule binding causes the receptor protein to undergo a conformational change (a change in shape). At this point the receptor protein can interact with another molecule.

Detailed explanation-4: -Ligand-Gated Ion Channels Binding of ligand to the exofacial surface of the receptor generates a conformational change that results in the opening of a pore, allowing specific ions to travel through the channel across the plasma membrane (Fig. 2.2).

Detailed explanation-5: -If the neurotransmitter binds to an ion channel receptor on the target cell, the related ion channel opens, and an electrical signal propagates itself along the length of the target cell. Neurons have ion channel receptors specific to many kinds of neurotransmitters.