LIFESCI 2 Lecture Notes - Lecture 8: Extracellular Matrix, Plasmodesma, Metastasis
Document Summary
Receptor triggers a series of events called signal transduction: signal transduction: one molecule activates the next and so on. Signal often amplified at each step in the pathway. Result = low signal concentration can have a large effect on responding cell: cellular response: can activate enzymes, turn on genes, change shape, or signal other cells, termination: cellular response is stopped. Protects cell from overreacting to existing signals: endocrine signaling acts over long distance, signaling that travel through bloodsteam, ex. ) Transmit signal signal from outside to inside of cell. G-protein has two states: on or off. Signals often amplified in cytosol: receptor kinases: enzyme that catalyzes transfer of phosphate group from atp to substrate. Must bind to both atp & substrate to catalyze reaction = phosphorylation (gene usually switched on) Phosphorylation important bc it affects activity of substrate. Phosphatases removes phosphate group = dephosphorylation (gene usually switch off) Ion channels = alter flow of ions across plasma membrane.
