AP BIOLOGY

Detailed explanation-1: -(A) cAMP is the archetypical second messenger. Its levels increase rapidly following receptor-mediated activation of adenylyl cyclase (AC), which catalyzes the conversion of adenosine monophosphate (AMP) to cAMP.

Detailed explanation-2: -Examples of second messenger molecules include cyclic AMP, cyclic GMP, inositol triphosphate, diacylglycerol, and calcium.

Detailed explanation-3: -The action of epinephrine illustrates the principles by which cyclic AMP mediates hormone action. Epinephrine is the “flight or fight hormone” that the adrenal glands release in response to stress. The hormone causes an increase in blood pressure and the breakdown of glucose for energy.

Detailed explanation-4: -What are second messengers? Signals received by receptors at the cell surface or, in some cases, within the cell are often relayed throughout the cell via generation of small, rapidly diffusing molecules referred to as second messengers.

Detailed explanation-5: -Cyclic adenosine monophosphate (cAMP) was the original “second messenger” to be discovered. Its formation is promoted by adenylyl cyclase activation after ligation of G protein–coupled receptors by ligands including hormones, autocoids, prostaglandins, and pharmacologic agents.