AP BIOLOGY

Detailed explanation-1: -A signal is detected when the chemical signal (also known as a ligand) binds to a receptor protein on the surface of the cell or inside the cell. 2. Transduction: When the signaling molecule binds the receptor it changes the receptor protein in some way. This change initiates the process of transduction.

Detailed explanation-2: -6.1. Following ligand binding, HSP90 is released and the receptor rapidly translocates to the nucleus. Steroid receptors function as transcription factors, thus once in the nucleus they bind to specific steroid response elements on the DNA.

Detailed explanation-3: -Receptor/ligand binding affinity. The interaction of ligands with their binding sites can be characterized in terms of a binding affinity. In general, high-affinity ligand binding results from greater attractive forces between the ligand and its receptor while low-affinity ligand binding involves less attractive force.

Detailed explanation-4: -The binding of a ligand to most RTKs will result in the ligand-induced dimerization of these receptors, which will subsequently lead to a process known as autophosphorylation.