BIO 211 Lecture 10: Week 5 class 1
15 Feb 2017
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Document Summary
Metazoans have intermediate filaments that form a cytoplasmic filament: prominent in cells that undergo mechanical stress, not found in species with rigid exoskeletons. Cytoplasmic intermediated filaments are related to nuclear lamins: nuclear lamins= anchor sites for chromosomes and nuclear pores. Intermediate filament structure depends on the lateral bundling and twisting of coiled-coils. 3 types: nf-l, nf-m, nf-h, desmin- filaments in skeletal, cardiac, and smooth muscle, forms scaffold around z disc. Linker proteins connect cytoskeletal filaments and bridge the. Involved in cell division, migration, and vesicle trafficking: gtp required to bind for folding to occur. Cell polarization and migration: many cells can crawl across a solid substratum, many cells crawl and do not use cilia or flagella. Leading edge protrusion allows locomotion: different cells generate different protrusions, filopodia- one-dimensional structures formed for neurons cones and fibroblasts, core of actin, lamellipodia- 2-dimensioanl structures formed form fibroblasts, epithelial cells, and some neurons, cross-linked mesh of actin.
