BI110 Lecture Notes - Lecture 12: Glycogen, Insulin, Blood Sugar
Document Summary
Signals are transmitted from the receptor to a response in cell by a series of biochemical reactions, usually involving protein kinases. Kinases are enzymes that transfer a phosphate group from atp to one or more sites on particular target proteins (phosphorylation of a target protein) The added phosphate groups stimulate or inhibit activities of the target proteins. Often , target proteins in singal transduction cascades are other kinases. Respo(cid:374)ses (cid:272)a(cid:374) (cid:271)e (cid:396)eve(cid:396)sed (cid:894)o(cid:396) (cid:862)tu(cid:396)(cid:374)ed off(cid:863)(cid:895) (cid:271)y removing phosphate groups from target proteins always active. Phosphorylation cascade: receptor (bound to the singal molecule ligand, when the receptor gets turned on it transducts by phosphorylation cascade, then there is activation of inactivation of target molecules, which then triggers the response. Signal enzyme activates 10 of the first molecules in pathway: each of these activates 100 of the second enzyme in pathway, producing 1000 activations, continued amplification of signal.