BCHM 210 Study Guide - Midterm Guide: C2 Domain, Endoplasmic Reticulum, Phospholipase C
Document Summary
Inositol 1,4,5-triphosphate (ip3: ip3 interacts with a ca++ channel, the ip3 gated channel or receptor (similar to k+ channel), this interaction opens the channel causes a rapid release of ca++ stored in. Er and sr: elevated ca++ triggers many responses including smooth muscle contraction, glycogen breakdown and vesicle release, the ip3 signal is short lived because it is rapidly degraded to metabolites that do not affect the channel. Ip3 is one of the two second messengers made after phospholipase c cleaves pip2. Ip3 opens calcium channels: the calcium in the cytoplasm of cells is low, so when ip3 opens up the calcium channels. The calcium stored in the endoplasmic reticulum and sarcoplasmic reticulum is rapidly released: this ultimately leads to smooth muscle contraction, glycogen breakdown and vesicle release. The way its turned off is because ip3 is not a very stable molecule (boxed) so it can be converted to any of the other species diagramed above.