W6 - COMPONENTS PLASMA MEMBRANE

Triglyceride (lipid)

• solid (fats) or liquid (oil)

• stored energy (largest)

• insulation and protection

Phospholipid (lipids)

• modified triglyceride

  • amphipathic

• cell membranes

• 2 tails instead of 3

cholesterol (lipid)

• cell membrane

• steroid hormones

• vit d

• bite salts

Semi-permeable phospholipid bilayer

• phospholipids arranged as a bilayer

  • amphipathic - water loving and hating component

  • hydrophilic (polar) head that can be contacted w/ water

  • hydrophobic (non-polar) tail move away from water

• water-soluable substance cannot cross phospholipids

• lipid-soluable substances can cross plasma membrane

carbohydrates

• sugars and starches

  • monosaccharides

  • disaccharides

  • polysaccharides

• larger CHOs are less soluble

• functions:

  • Energy (glucose)

  • structural material - cell membrane, DNA/RNA

proteins

Plasma (cell) membrane

• selectively permeable barrier surrounding cells

• separates ECF and ICF

• membrane proteins

  • peripheral on surface

  • integral embedded

• cholesterol = stability but allows for fluidity

• carbohydrates = recognition (identifying cells)

membrane proteins