lipids

• lipids

  -glycerol+ fatty acid
• glycerol

  The H from glycerol and OH from fatty acid react together during a condensation reaction to release water and form an ester bond.

  
• Triglyceride 


  = combining one glycerol molecule with 3 fatty acids.

  
• Saturated lipids

  -every carbon atom is bonded to as many hydrogen atoms as possible.

  -can pack together to form solid fat at room temperature.

  -carbon chain is straight with no kinks.

  -mainly found in animal fats from meat and dairy products.
• unsaturated lipids

  -not every carbon atom is bonded to as many hydrogen atoms as it could so there are double bonds present.

  -double bonds introduce a kink in the carbon atom chain.

  -the more double bonds the more kinks.

  -don't pack together easily, forms liquids a room temperature.

  -mainly found in vegetable oils, nuts, fish
• phospholipid

  = one of the fatty acids in a triglyceride is swapped for a phosphate group.

  • they have a non-polar end (fatty acid) and a charged end (phosphate group)
  • non-polar end are repelled by water=hydrophobic
  • charged end is attracted to water= hydrophilic
  • bilayer= all hydrophobic ends pointing towards each other heads- hydrophilic attract to the water.
• emulsion test 


  1-sample mixed with ethanol

  2-water is added+ shaken

  3-if white emulsion forms as a layer on top of the solution, this indicates the presence of a lipid.
• lipids and health

  -sterols are a lipid they have a hydrophilic+ hydrophobic end, hydroxyl group is polar.

  • cholesterol= made in liver, polar end, 4 carbon ring structure, role in formation of cell membrane, regulates cell membranes fluidity (too hot=too fluid, too cold=too rigid), can be used to make hormones, vitamins, bile
  • uses= electrical insulation necessary for impulse transmission, membrane formation and creation of hydrophobic barriers.