BIO 111 Lecture Notes - Lecture 9: Autocrine Signalling, Paracrine Signalling, Signal Transduction
Document Summary
Cells need to talk to each other also. Signals: agents that influence the properties of cells. Signals relayed between cells: direct intercellular signaling, contact dependent signaling, autocrine signaling. A cell is telling itself to do something: paracrine signaling. Signal affects cells in close proximity (synaptic signaling: endocrine signaling. Signals travel to cells further away in the body. Signaling molecule binds to receptor: signal transduction. Activated receptor induces a signal signal transduction pathway: cellular response. Once ligand is released, receptor is no longer activated. Most = protein kinases (transfers phosphates from atp to proteins) Activated receptor binds to g protein in cell. Lingands bind to receptor, it opens up a channel. Growth factor: hormone that signals cell to grow or divide. Signals binded to cell surface are first messenger. Alpha unit binds to adenyl cyclase to produce camp. Variation in response determined by types of proteins that each cell makes. Enzyme removes camp once a signaling molecule is no longer present.
