Essential Cell Biology Chapter 17 Cytoskeleton Exam Questions and Answers

Cytoskeleton - ANSWER-•A network of proteins that extend throughout the cytoplasm as well as the nucleus What are the functions of the cytoskeleton? - ANSWER-•Cell shape •Movement •Cell Adhesion •Intracellular traffic •Cell division •Other specialized functions What are the 3 types of protein filaments found in the cytoskeleton? - ANSWER-•Intermediate filaments •Microtubules •Actin filaments Intermediate filaments - ANSWER-•Most stable and durable of all cytoskeletal fibers •Extend across cytoplasm •Subunits: large & diverse family of proteins •Functions: enable cells to withstand mechanical stress Assembly of intermediate filaments - ANSWER-•Eight tetramers twisted into a rope-like filament •10 nanometers wide Intermediate filaments provide cell strength - ANSWER-•The intermediate filaments in epithelial cells extend across the cytoplasm of cells connected to each other in a sheet. •The sheet of cells remains intact when stretched •If no IFs present, the cells would rupture when stretched Desmosomes - ANSWER-•Joins the intermediate filaments in one cell to those in a neighbor