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.
Norepinephrine is also made in the adrenal medulla where it synthesized from dopamine and is released into the blood as a hormone. Epinephrine is made from norepinephrine inside the adrenal medulla (the inner part of the adrenal gland, a small gland associated with the kidneys). Our adrenal medulla helps us to cope with physical and emotional stress. The synthesis of epinephrine increases during times of stress.