HLSC 2P09 Chapter 6: HLSC 2P09
Document Summary
Signaling through 7 tm receptors : g-protein- adenylyl cyclase. !1: signal molecule binds to g protein-linked receptor, which activates the g protein. Ip3 causes release of ca2+ from organelles, creating a ca2+ signal. Signaling molecules regulating ion channels: receptor-channels open or clase in response to signal molecule binding, some channels are directly linked to g proteins, other ligand-gated channels respond to intracellular second messenger. Ca 2+ :and intracellular messenger: intracellular [ca++ ] (resting) 0. 01-0. 1 um (10-7 m, extracellular [ca++ ] 2-5mm (10-3 m) Release into cytosol: ca++ channels in pm, voltage gated ca++ channels in pm ip3 gated ca++ channels in er ryanodine receptors in sr. No, a simple gas, is able to diffuse across the membrane, and alters the activity of intracellular target enzymes. It"s extremely unstable, so its effects are local. Receptors associated with tyrosine kinase: tm receptors, growth hormone. Signal transduction by receptors associated with a tk: