PATH 2800

08/31

• Cell Membrane = mix of lipids and proteins

  • Multiple functions

  • selective barrier

  • Components

    • Lipids = Hydrophobic effect / effects the shape and composition

    • Lipids are dynamic bc its in a constant state of remodeling

• Lipid

  • Head = Hydrophilic

  • Tail = Hydrophobic

• Phospholipids (4) = all have unique backbone and head

  • PC *

  • PS *

  • PE

  • SM

    • All Phospholipids are amphipathic/ Polar head (purple) and 2 tails (orange & Grey)

  • Composition of phospholipids arnt random and serve a purpose for the function

  • Cholesterol Lipids

    • Slows down lipids (Fatty acid / hydrophobic chain)

  • Glycolipids

    • Only found in outer lipid membrane

    • w/ attached sugar residues

    • good as a cell receptor / signaling/ interacting

  • Membrane Lipids - Turnover

  • 1

  • 2 = Oxidative Damage and Repair

    • oxy binds itself to the fatty acid tail and causes bending that may cause it to break

    • (Oxygen species like peroxide)

  • 3= enzymatic lipid metabolism

    • Phospholipases+

    • liver damages using multiple inhibitors

09/02

cholesterol slow down phospholipids

protein+lipid+cholesterol = packing

lipid Movement

• Proteins good for moving lipids sheilding its tails

  • Fatty acids (acytl coa bind or albumin)

  • HDL - good/ higher protein / healthy

  • LDL - bad / plaque formation blood

• Good vs bad cholesterol

Lipid exchange proteins

• Flipse = inhibid by ca+

• Scramblas = activated ca+

• Symetrical equilibrium not good could cause cell death

Memebrane movment

• similar to lipids but cant flip flop