BIO230H1 Lecture Notes - Lecture 7: Paracrine Signalling, Signal Transduction, Quorum Sensing

• School: UTSG
• Department: Biology
• Course: BIO230H1
• Professor: Christopher M Yip

Document Summary

Examples of unicellular communication: quorum sensing in bacteria, mating in budding yeast, aggregation of ameboid cells. Cells receive signals in 2 main ways (depends on whether the signal is hydrophobic or hydrophilic): cell-surface receptors, intracellular receptors, short-distance signalling. Contact-dependent signalling signals are received on the cell surface (the shortest distance); Paracrine signalling signals are released from the cell but act locally (signal goes a little bit further, relatively "local"); Synaptic signalling neurons extend axons to contact distant target cells and the released sugnaling molecules act locally at target; Endocrine signalling endocrine cells secrete hormones into the bloodstream for long- range distribution; Signal transduction the conversion of extracellular signal into intracellular signals. Effector a downstream molecule in a signal transduction pathway. Second messenger small intracellular signaling molecules made in large numbers, which diffuse through the cytoplasm or plasma membrane and bind and alter effector molecules. There are also large intracellular signaling molecules, which are organized into pathways and networks.