BI110 Lecture Notes - Fluid Mosaic Model, Lipid Bilayer, Passive Transport
Document Summary
Lipids in either side of the bilayer can move, but not switch between layers. 5. 2b membrane fluidity the fluidity of the lipid bilayer is dependent on how densely the individual lipid molecules can pack together. Composition of the lipid molecules: more unsaturated fats on the tails results in a more fluid membrane. Temperature: the lower the temperature the more densely the molecules are packed (less movement) Transport - of substances into and out of the cell through channels, or transport proteins. Enzymatic activity - enzyme membrane proteins such as those associated with the electron transport chain. Signal transduction - receptors that bind to signal molecules such as hormones that. Attachment/recognition - attachment points for a range of cytoskeleton elements, as well as components involved in cell to cell recognition. Simple: ie. hydrophobic molecules, small, uncharged polar molecules, facilitated diffusion, transport facilitated by protein complexes that span the membrane, still driven by the concentration gradient.
