01:119:101 Lecture Notes - Lecture 2: Signal Transduction, Quorum Sensing, Cell Signaling
Document Summary
External signals are converted to responses in the cell. Cells send out a mating factor that binds to receptors on the other cell type. Binding of the factors to receptors induces changes in the cells. Transduction: the signal is changed into a form that brings about the cellular response. Signal transduction pathway: the series of steps taken for a received signal to convert to a specific cellular response. Concentration of signaling molecules allows them to monitor local cell density (quorum sensing) coordinate behaviors so they can carry out activities that are only productive when performed by n cells in synchrony, like biofilm formation. Direct contact (animals & plants): cell junctions that directly connect the cytoplasms of adjacent cells; substances dissolved in the cytosol can pass freely. Cell-cell recognition (animals): membrane-bound cell-surface molecules; key in embryonic development. Paracrine signaling: messenger molecules are secreted by the signaling cell.