1. Bio 178 Lecture 9 Cell Structure Copyright: E.G. Platzer

2. Reading Chapter 5 Quiz Material Questions on P 104 Chapter 5 Quiz on Text Website (www.mhhe.com/raven7)

3. Outline Eukaryotic Cells (Cntd) 1.Cytoskeleton (Cntd.)

4. The Cytoskeleton

5. Intermediate Filaments Microtubules Actin Filaments http://www.tmd.ac.jp/artsci/biol/textbook/cellmove.htm

6. Actin Filaments in Melanoma Cell http://cellix.imolbio.oeaw.ac.at/Videotour/video_tour_5.html

7. Microtubules Size ~ 25 nm diam Composition Hollow tubes - 13 protofilaments. Each subunit - tubulin heterodimer of  - and  - tubulin monomers. http://www.tmd.ac.jp/artsci/biol/textbook/cellmove.htm

8. Microtubules Functions Movement of organelles Chromosome movement

9. Microtubules in Fish Fibroblast Cell http://cellix.imolbio.oeaw.ac.at/Videotour/video_tour_12.html Cy tubulin growing into adhesion sites

10. Intermediate Filaments http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Cytoskele ton.html

11. Intermediate Filaments Size 8-10 nm Composition Ropes of a heterogeneous mix of fibrous proteins (eg. vimentin, keratin)

12. Intermediate Filaments Stability Post-formation do not usually break down. Functions Support

13. Centrioles

14. Centrosome The primary microtubule organizing center of animals and acts as the spindle pole during mitosis. Usually contains a pair of centrioles. Located near nucleus. Structure Not membrane-bound. 9 triplets of microtubules. “The centrosome is the main microtubule organizing center (MTOC) of the cell. It is composed of two orthogonally arranged centrioles surrounded by an amorphous mass of pericentriolar material (PCM)”. http://en.wikipedia.org/wiki/Centrosome The Centriole

15. The Centriole (cntd) Kingdoms Animals and some protists Functions Microtubule assembly Anchor of cilia and flagella (basal bodies) http://www-cteu.u-bourgogne.fr/cav/dicobio/fiches/centriole.html

17. Dynein

18. Molecular Motors Description Proteins that transport organelles, chromosomes, and vesicles using the cytoskeleton as a “highway”. Use ATP for energy. Motor Types Differ in the type of filament they bind to, cargo they carry, and directionality. Examples - Dynein, kinesin, myosin.

19. Directionality of Kinesins & Dyneins http://www.tmd.ac.jp/artsci/biol/textbook/cellmove.htm

20. Muscle – Actin & Myosin http://www.tmd.ac.jp/artsci/biol/textbook/cellmove.htm

21. Myosin and Actin Video Alberts et al.: Molecular Biology of the Cell, 16.8