FIRST PUBLISH OCTOBER 2024
BIO 353 Exam 4 Study Guide Lecture 20
Study Guide
define cytoskeleton - Ans:✔✔-a network of filaments or tubes composed of protein subunits and
associated proteins
what are the three structural elements that constitute the cytoskeleton - Ans:✔✔-intermediate
filaments, microtubules, and actin filaments
what are the primary functions of the cytoskeleton - Ans:✔✔-cell motility, intracellular motility,
cytoplasmic order, and cell and tissue shape and support
what are the characteristics of intermediate filaments - Ans:✔✔-tough ropelike fibers, do not bind
nucleotides, form structurally non-polar filaments, provides mechanical support to cells and tissues
what is the subunit of intermediate filaments - Ans:✔✔-intermediate filament protein
are intermediate filaments structurally polar - Ans:✔✔-no they are non-polar
do intermediate filaments have associated motor proteins - Ans:✔✔-no, they are not directly
responsible for generating intra-cellular movements
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what is the primary function of intermediate filaments - Ans:✔✔-impart strength providing mechanical
support to cells and tissues
what are some examples of cytoskeletal structures that consist of intermediate filaments - Ans:✔✔-
keratin filaments, neurofilaments, and nuclear lamins
what is keratin - Ans:✔✔-epithelial cellular and tissue support
what is plectin - Ans:✔✔-intermediate filament accessory protein
what does plectin do - Ans:✔✔-further stabilizes and reinforces network by cross-linking intermediate
filaments into bundles and links them to microtubules, actin filaments, and adhesive structures in
desmosomes
what is epidermolysis bullosa simplex - Ans:✔✔-a rare mutation in keratin gene produces defective
filament assembly resulting in weakened keratin network; cell layer is highly susceptible to mechanical
trauma from rubbing of the skin during movement causing non-scarring blisters disease; no cure
what are lamins - Ans:✔✔-intermediate filaments found in nuclei of all eukaryotic cells
what is the nuclear lamina - Ans:✔✔-interconnected web of filaments that underlies the inner nuclear
membrane
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