Biology 2581B Study Guide - Quiz Guide: Polymerization, Spindle Apparatus, Depolymerization

• School: Western University
• Department: Biology
• Course: Biology 2581B
• Professor: Susanne Kohalmi

Document Summary

Microfilaments: g actin monomer- c. 7nm diameter filaments. Filament formation non-covalent interactions (thus dynamism (de)polymerisation) but v strong. Intracellular transport tracks: atpase activity, double helix, 7nm diameter. Globular (hence g) monomer: 43kda: adhesion, mitotic spindle orientation, contractile e. g. actomyosin cytokinetic ring, myofibrils, stress fibres. All eukaryotic cells most abundant cell protein, esp muscle cells 10% Enriched just beneath membrane strength, support: atp / adp binding cleft (between 2 lobes) don"t work with other nts. Initial lag" phase: could just increase [salt] in vitro. Atp dependency: so [critical] = koff/kon i. e. kd, + end: addition, below [critical] net depolymerisation, kon[critical] = koff, better self-association. [free monomer] at this state = [critical: eqm multiplied by free capping, but can only do that @ end: t capping prevents if sufficiently [high t form] Incorporation new balances loss steady state: above [critical] net polymerisation, depolymerisation not dependent on [monomer] polymerisation decreases [monomer] reduce forward rxn product, preferential incorporation atp bound t form actin".