Biomembranes and Cell Architecture - PowerPoint

							      Chapter 5:
Biomembranes and Cell
     Architecture
   By: Anna Whiteshield
                Overview

 Lipid Composition
 Protein Components
 Organelles of Eukaryotic Cell
 Cytoskeleton
 Purification of Cells
 Visualizing Cell Architecture
Overview of the cytoskeleton
     Three types of filaments in the
                cytosol
   Actin also known as Microfilaments

   Microtubules

   Intermediate filaments
    Organization of the filaments
   Bundles
       Filaments   are closely packed in parallel arrays.


   Networks
       Filaments   crisscross at right angles and loosely
       packed.
                 Microfilaments

   Structural support and motility
        Actin



   Composed of polymerized α- and β-tubulin

    Membrane-microfilament binding proteins
    connect them to the membrane
         Intermediate Filaments
   Support for Nuclear membrane
        Lamins



   Cell adhesion
        Desmin,   keratin, vimentin.


   Motility
        MSP
                   Microtubules
   Structural support, motility, cell polarity
       α   and β Tubulin


   Cell division (bacteria)

   Necessary for endoplasmic reticulum
    location and formation of mitotic apparatus
                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.
                     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. 2004.
    Biomembranes and Cell Architecture. P.174-178.
    Molecular Cell Biology. W.H. Freeman and Company,
    New York.