BIOLOGY 172 Lecture Notes - Lecture 11: Membrane Protein, Plasmid, Uniporter
Document Summary
Membrane"s posses a fluid quality: phospholipids drift within one side, don"t usually flip due to difficulty of crossing hydrophobic nonpolar region by polar heads, fluidity is enhanced by unsaturated fatty acid tails, cholesterol stabilizes membrane, largely hydrophobic. Steroids: cholesterol: a type of lipid, include cholesterol, component of animal membranes; animals don"t have cell walls, so steroids support them, cholesterol is a precursor for estradiol and testosterone, amphipathic, but mostly hydrophobic e. Interacts with fatty acid tails of membrane to stabilize it: provides rigidity and decreases fluidity at normal to high temps and increases fluidity at low temps, about 30% of animal membrane lipids. Integral membrane proteins: necessary to maintain integrity of membrane, spans bilayer, temporarily associated with one side of the membrane, peripheral membrane proteins. Bacterial and eukaryotic cells: what"s the difference, bacteria lack nuclear membrane lack membrane bound organelles. Includes dingle circular chromosome plasmid: nucleoid area where chromosome is located, cytoskeleton, flagellum.
