1 / 19

Cytoskeleton

Cytoskeleton . Network of protein fibers extending throughout the cytoplasm Function in providing for both structural support and cell motility Require interaction of the cytoskeleton with motor proteins Three main kinds of fibers make up the cytoskeleton:. Figure 7.20 The cytoskeleton.

xia
Download Presentation

Cytoskeleton

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cytoskeleton • Network of protein fibers extending throughout the cytoplasm • Function in providing for both structural support and cell motility • Require interaction of the cytoskeleton with motor proteins • Three main kinds of fibers make up the cytoskeleton:

  2. Figure 7.20 The cytoskeleton

  3. Table 7.2 The structure and function of the cytoskeleton

  4. Microtubules • Hollow rods • Composed of globular proteins called tubulins • Functions: • Cellular support • Tracks for organelle movement • Separation of chromosomes during cell division • Involved in the motility of the cell

  5. Figure 7.x3 Actin

  6. Figure 7.x4 Actin and keratin

  7. Centrosomes and centrioles • Centrosome – region located near the nucleus • Centriole – pair of cylindrical structures located in the centrosome of animal cells • Composed of nine sets of triplet microtubules arranged in a ring • May organize microtubule assembly during cell division

  8. Figure 7.22 Centrosome containing a pair of centrioles

  9. Cilia and flagella • Locomotor organelles formed from a specialized arrangement of microtubules • Unicellular eukaryotic organisms are propelled through water by cilia or flagella • Motile sperm cells (animals, algae, some plants) are flagellated • May function to draw fluid across the surface of stationary cells (ciliated cells lining trachea)

  10. Figure 7.23 A comparison of the beating of flagella and cilia

  11. Figure 7.23x Sea urchin sperm

  12. Figure 7.21 Motor molecules and the cytoskeleton

  13. Figure 7.24 Ultrastructure of a eukaryotic flagellum or cilium

  14. Figure 7.25 How dynein “walking” moves cilia and flagella

  15. Microfilaments (actin filaments) • Solid rods • Composed mainly of proteins called actin • Function: • Helps supports the cell’s shape • Participate in muscle contraction • Responsible for localized contraction of cells (dividing animal cell)

  16. Microfilaments function (cont.) • Elongation and contraction of pseudopodia during amoeboid movement • Involved in cytoplasmic streaming found in plant cells • Cytoplasmic streaming (cyclosis) – flowing of the entire cytoplasm around the space between the vacuole and plasma membrane in a plant cell

  17. Figure 7.26 A structural role of microfilaments

  18. Figure 7.27 Microfilaments and motility

  19. Intermediate filaments • More permanent than microtubules or microfilaments • Constructed from keratin subunits • Function: • Specialized for bearing tension • Reinforce cell shape • Fix organelle position

More Related