1. Chapter 5: Biomembranes and Cell Architecture
By: Anna Whiteshield

2. Overview Lipid Composition Protein Components
Organelles of Eukaryotic Cell
Cytoskeleton
Purification of Cells
Visualizing Cell Architecture

3. Overview of the cytoskeleton

4. Three types of filaments in the cytosol
Actin also known as Microfilaments
Microtubules
Intermediate filaments

5. Organization of the filaments
Bundles
Filaments are closely packed in parallel arrays.
Networks
Filaments crisscross at right angles and loosely packed.

6. Microfilaments Structural support and motility
Actin
Composed of polymerized α- and β-tubulin
Membrane-microfilament binding proteins connect them to the membrane

7. Intermediate Filaments
Support for Nuclear membrane
Lamins
Cell adhesion
Desmin, keratin, vimentin.
Motility
MSP

8. Microtubules Structural support, motility, cell polarity
α and β Tubulin
Cell division (bacteria)
Necessary for endoplasmic reticulum location and formation of mitotic apparatus

9. Summary
Cytoskeleton provides structural stability and movement for the cell.
Microfilaments and their proteins form a skeleton underneath the plasma membrane
Intermediate filaments mediate cell-cell adhesion and cell-matrix adhesion.
Microtubules radiate from centrosome forming the MTOC.

11. References: http://bio.winona.edu/bates/Bio241/cells.htm
Lodish,H.,A. Berk, P. Matsudaira, C.A. Kaiser, M. Krieger, M.P. Scott, S.L. Zipursky, and J. Darnell Biomembranes and Cell Architecture. P Molecular Cell Biology. W.H. Freeman and Company, New York.