G. An explanation of the Genetic Code: DNA is a two-stranded molecule. Each strand is a polynucleotide composed of A (adenosine), T (thymidine), C (cytidine), and G (guanosine) residues polymerized by dehydration synthesis in linear chains with specific sequences.
Note: There are more than two types of epinephrine receptors on smooth muscle cells, so epinephrine may affect smooth muscle in other tissues in other ways. (There are subtypes of alpha and subtypes of beta.) * Details of how PLC generates IP3 are on handout 12A. We will go over this later.
Epinephrine, a catecholamine secreted by the adrenal gland, is an important CNS neurotransmitter and has a central role in autonomic regulation including intestinal and bronchial smooth muscle tone, vascular tone, glucose metabolism, and cardiac rate and contractility.