BIOL 1201 : FINAL REVIEW SESH
Document Summary
11. 16: where are the receptors involved in cell signaling located, may involve a receptor in the plasma membrane, an integral membrane protein, fig. 11. 6: may involve an intracellular receptor (inside cell; cytoplasm, e. g. , steroid hormone receptors, fig. Cell signaling: g protein: switch protein, either on or off, activated by occupied (activated) receptor, gdp is bound to the alpha subunit of the inactive g protein hererotrimer (protein made of three different units) Inactive, off: alpha gdpbetagamma: active, on: alpha gtp + betagamma. Cell signaling: activation of g proteins: alpha subunit with gtp bound and a beta gamma dimer. Viii: an activated receptor interacts with the g protein, gtp replaces gdp on the alpha subunit, the g protein dissociates in alpha-gtp and a betagamma dimer, the g protein is now on. Interact with their target enzymes or ion channels. Cell signaling: inactivating g proteins: alpha gdp and the betagamma dimer reassociate.
