BIO 211 Study Guide - Comprehensive Final Exam Guide - Protein, Neuron, Cytosol
Document Summary
Euks have three basic types of cytoskeletal elements: microtubules, composed of the protein tubulin and are 25 nm in diameter, microfilaments, composed of the protein actin and are 7 nm in diameter; microfilaments are polymers of actin. = cytoskeleton: the interior of a cell is highly structured, the cytoskeleton is a network of interconnected filaments and tubules extending through the cytosol, plays a role in cell movement and division. Mg2: critical step in formaton is the aggregation of tubulin dimers into clusters called oligomers, act as seeds where new mts can grow. Gtp (cid:271)y -tubulin eventually results in an unstable tip, depolymerization may rapidly occur: microtubule catastrophe: switch from growth to shrinkage. If concentration of gtp-tubulin falls, the rate of tubulin addition decreases. Interphase of the cell cycle --> mtocs are centrosomes that are near the nucleus. Cell division duplicates centrosomes and creates new mtocs for each of the daughter cells: centrioles = formed by nine sets of triplet microtubules.
