exam 2 material

exam 2 material - 25/09/200800:05:00...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
25/09/2008 00:05:00 CELL MEMBRANE MODELS  (plasma membrane):               Fluid-Mosaic Model               2 layers of phospholipids as before, but now exposed              proteins in a mosaic patterns, not a continuous layer              pores bounded by protein as before              fluidity: proteins and phospholipids can move (dynamic structure),  evidence from hybrid cells          Cell Coats:      (not a separate entity from the cell membrane)                                                glycocalyx composed of glycolipids, glycoproteins      Why do membranes exist ???               A)        structural    B)              Functional properties:     
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
  Biological Systems: (with membranes)                                                                    Osmosis:  net movement of water across a semi-permeable membrane                                                              (ie permeable to water, but not to solutes)                  Relative Relationship:         Terminology of Solutions Relative to one another:                 Hyperosmotic:                Isosmotic:                Hypoosmotic:        Factors involved in the permeability  
Background image of page 2
                                    * size and shape of molecules                                      * solubility in lipids                                      * net electric charge                                      * chemical properties                          ------But water moves freely across the membrane------                                      * important to study the movement of water                                                  ** water is the universal solvent in biological  systems      Movement of Substances Across Membranes:               A)  Many substances can move by diffusion, since the membrane is  permeable to them (simple  sugars, amino acids, lipids)                B)  membrane is impermeable to many other substances (ions, complex  sugars, proteins, other  large molecules) 
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 27

exam 2 material - 25/09/200800:05:00...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online