BIOL 1090 Study Guide - Final Guide: Intermediate Filament, Depolymerization, Microfilament

• School: University of Guelph
• Department: Biology
• Course: BIOL 1090
• Professor: Dan Meegan

Document Summary

Dynamic network of protein filaments that forms the cellular scaffolding as well as transport system for organelles and vesicles. Intracellular transport: structural support, contractility and motility, spatial organization within a cell. Major elements: microtubules: hollow, unbranched tubules of tubulin, microfilaments: solid, thin, branched, actin polymers. Heterodimers aligned in the same direction (head to tail) structural polarity. 13 protofilaments form longitudinal array hollow cylinder: fast growing + end (top of figure, slow growing end (bottom of figure) Structural polarity is important for growth/shrinkage and direction of movement of material along mt. Dynein (minus end directed) and kinesin (plus end directed) can power intracellular transport. In vivo, leads to rapid turnover of most mts within cell (half-life is minutes: dynamic instability. Catastrophe- shrinkage can occur very rapidly at the plus end: can be growing on one side and disassembling on the other so it is moving but stationary. Formation of mts is regulated/controlled (microtubule associated proteins- maps)