BIOL 1107 Lecture Notes - Lecture 9: Signal Transduction, Quorum Sensing, Paracrine Signalling
Document Summary
Cells communicate using chemical signals that bind to specific receptors. Signaling involves receptor activation, signal transduction, response, and termination. Receptor activation: a signal molecule binds to a receptor and the receptor is turned on (activated): usually does activation by causing a conformational change in the receptor. Signal transduction: o(cid:374)e (cid:373)olecule acti(cid:448)ates the (cid:374)ext (cid:373)olecules, (cid:449)hich acti(cid:448)ates the (cid:374)ext : chain reaction/cascade of biochemical events set off by the binding and activation of a receptor, signal often amplified at each step in the pathway. As a result, a low signal concentration can have a large effect on the responding cell. Response: takes different forms depending on the nature of the signal and the type of responding cell. Termination: cellular response is stopped: protects the cell from overreacting to existing signals and therefore helps the cell to have an appropriate level of response, allows cells to respond to new signals. 9. 2: cell signaling over long and short distances.