BIO 311C Chapter Notes - Chapter 11: Gtpase, Itri, Tyrosine
Document Summary
Protein kinase cuts phosphate off atp and transfers it to a protein, activating it. Protein phosphatase removes phosphate from protein, deactivating protein. Second messengers inside cell; can move easily around cytoplasm, small. Release of calcium ions into the cytosol serves as a trigger. Signal amplification at ea(cid:272)h step i(cid:374) the path(cid:449)a(cid:455) there"s a large i(cid:374)(cid:272)rease i(cid:374) the (cid:374)u(cid:373)(cid:271)er of a(cid:272)ti(cid:448)ated molecules. Signal transduction pathway in taste buds one sugar molecule can trigger a pathway. Prevents molecules from leaking out of dying cells and damaging neighboring cells. Plasma membranes of neighboring cells are very tightly pressed against each other. Establishes barrier that prevent extracellular fluid from leaking. E. g. tight junctions between skin cells make us watertight. Provide cytoplasmic channels from one cell to an adjacent cell. Consists of membrane proteins that surround a pore. When cell junctions directly connect cytoplasms of adjacent cells and signaling substances can pass freely between adjacent cells.
