BIOL 1020 Lecture Notes - Lecture 9: Fluid Mosaic Model, Lipid Bilayer, Membrane Fluidity

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 1020
• Professor: Dr.Joy Stacey

Document Summary

Sandwich model - plasma membrane (9) -membranes chemically analyzed: found in proteins, lipids - knew it was phospholipid bilayer. Fluid mosaic model - plasma membrane (discoveries) -not a sandwich - fluid mosaic model. Peripheral protein, embedded in membrane, integral embedded around. Fluid mosaic model -fluid structures w/ a mosaic of proteins embedded in. Hydrophobic r groups of amino acids are in the fatty acid portion. Hydrophillic r groups associated w/ polar head groups. Some proteins on cytoplasmic layer not extracellular layer. The fluid in the fluid mosaic model -phospholipids move within the bilayer (laterally) Most of the lipids and some proteins drift laterally. Flip fatty acid upside down (flip flop once per month) Membrane fluidity - temperature temperature goes up: solid --> fluid. Membrane fluidity: fatty acid composition unsatured - prevents tight --> fluid saturated - tight --> not very fluid. Homeoviscous adaptation -change in fatty acid composition to counter temp. affects.