Cell/Plasma Membrane

Cell/Plasma Membrane - Fluid, semi-permeable phospholipid bilayer

• Fluid Mosaic Model - 2nd name for the plasma membrane since it is surrounded by water and made of many parts

• Phospholipids - made of phosphates, glycerol, and fatty acid tails

• Semi-permeable/Selectively permeable - only select things can get in; nonpolar molecules get in easiest (i.e. O₂ and CO₂)

• Amphiphilic - has parts that attract water and parts that repel water

  • Polar (+ and - charge) hydrophilic heads - attract water

  • Nonpolar (neutral charge) hydrophobic fatty acid tails - repel water

• Cholesterol (Steroid) - keeps membrane fluid by preventing it from falling apart in heat or freezing in cold

• Integral protein - go all the way through the membrane to transport things

• Peripheral proteins - sit on the edge of the membrane to receive signals; loosely attached

• Carbs - identify/label a cell

  • Glycoproteins - glycogen connected to a peripheral protein

  • Glycolipid - glycogen connected to a phospholipid