BIOL 112 Lecture Notes - Lecture 4: Basal Body, Tubulin, Spindle Apparatus

• School: McGill University
• Department: Biology
• Course: BIOL 112
• Professor: Jacalyn Vogel

Document Summary

Microfilaments usually at periphery of cell, near plasma membrane. Actin = ancient proteins, almost the same in plant and animal cells (? actin and myosin in muscle cells result in contraction. Microfilaments also involved in formation of pseudopods (lol amoebae), when actin starts to grow out as a bundle, depolymerise and contract, pulling the cell forward as it does so. Cells move around by actin and myosin binding (reversible), energy cycle. This bind and release linked to action of a molecular lever at head (how cells move forward) In some cells, microfilaments form meshwork just inside plasma membrane. Example: microvilli in human intestine, to increase surface area for absorption (not dynamic) o. Intermediate filaments: thicker than microfilaments, not as thick as microtubules (many polymers) Don"t grow and shrink so much - stable network in cells. Animal cells have these; plants, yeast don"t.