LIFE 120 Lecture Notes - Lecture 2: Intermediate Filament, Microfilament, Centrosome
Document Summary
Cytoskeleton is a network of fibers that organizes structures and activities in the cell. Cytoskeleton network extends throughout the cytoplasm: organizes the cells structures, anchors many organelles. Functions: supports the cell& maintains shape, regulates biochemical activities, produces cell motility. Components of the cytoskeleton: three main fibers make up the cytoskeleton. Microtubules are the thickest of the three components of the cytoskeleton. Microfilaments also called actin filaments, are the thinnest components. Intermediate filaments are fibers with diameters in the middle range: microtubules: hollow rods constructed from globular dimers called tubers. Moto(cid:396) p(cid:396)otei(cid:374)s atta(cid:272)h to (cid:448)esi(cid:272)les a(cid:374)d (cid:862)(cid:449)alk(cid:863) the(cid:373) alo(cid:374)g (cid:373)i(cid:272)(cid:396)otu(cid:271)ules using atp energy. In animal cells: centrosome has pair centrioles, each with nine triplets of microtubules in a ring. Microtubules control beating of cilia and flagella: flagella undulate to propel sperm cells, cilia go back and forth to propel protozoan, share a common structure. A basal body that anchors the cilium or flagellum. Dynein, the motor protein, drives the bending movements.