BMS 250 Chapter Notes - Chapter 4: Skeletal Muscle, Nucleoplasm, Microfilament
Document Summary
Ii: centrosome: is a structure typically in close proximity to the nucleus. It contains a pair of perpendicularly oriented cylindrical centrioles surrounded by protein that is amorphous. The paired centrioles are positioned perpendicular to each other with each composed of triplets of microtubules arranged in a circle. The primary function of a centrosome is organizing microtubules within the cytoskeleton. The centrosome is best known for its function in cellular division, during which microtubules form spindle fibers to facilitate chromosome movement. Proteasomes: large, barrel- shapes protein complexes, they are major protein digesting organelles located within both the cytosol and nucleus of cells. Atp-dependent pathways; these proteins include damaged proteins, incorrectly folded proteins, and normal proteins that are no longer needed by the cell. The action of proteasomes also provides a means to control the quality of exported cell proteins. This latter function is especially critical during the regulation of cellular metabolism, cell division, and activities associated with cell signaling.