Biology 2581B Study Guide - Quiz Guide: Intermediate Filament, Nuclear Membrane, Filopodia
Document Summary
The cytoskeleton gives the cell strength, shape and the ability to move. 3 families of protein filaments which can form polarized structures that are highly dynamic and therefore allow the cell to rapidly modify the cytoskeletal structure and function. They are most highly concentrated in the cortex, just beneath the plasma membrane. Intermediate filaments: intermediate in size, rope-like fibers made of intermediate filament proteins, provide mechanical strength, line the inner face of the nuclear envelope, hold epithelial sheets together, help extend axons, help form nails and hair. Actin subunits (g-actins) are amino acid polypeptides carrying a tightly associated molecule of. They assemble head-to-tail in a helix fashion to form a flexible right handed actin filament (f-actins), which is polar, with a slow growing minus-end and a fast growing plus-end. Accessory proteins cross-link and bundle these filaments together, to form larger and more rigid actin structures.