Biology 2382B Study Guide - Midterm Guide: Microfilament, Phalloidin, Cell Membrane

• School: Western University
• Department: Biology
• Course: Biology 2382B
• Professor: Robert Cumming

Document Summary

Cell shape and function; found at cortex- outside, just underneath plasma membrane. 4 lobes with a notch for atp binding; makes it polar. Can add myosin s1; arrow heads point to (-) end. G actin must be in atp form to polymerize. Hydrolysed into adp form-catches up afterwards like tubulin and gtp. (+) and (-) ends have different critical concentrations: (+) end 0. 12 m (-) end 0. 6 m. When in between the two cc; adding to(+)side and removing from (-) end (tread milling) Thymosin- bound to free g actin in cell; must release to polymerize. Profilin-promotes actin polymerization by changing g-adp to g-atp. Cap z- bind to and stabilizes (+) end. Tropomodulin- binds to (-) end and prevents disassembly. Form nuclei; nucleation step, steady state reached slower. Sit at (+) end, regulates growth, prevents capping of actin. Apr2/3 binds on to actin, branch grows from.