lipids &phospholipids

• Most lipids in our diet are triglycerides. ​These are fats and oils.
• Energy source-one molecule of triglyceride yields twice as many ATP ​molecules than glucose​

  Thermal insulation-lipids stored in adipose cells under skin help to retain heat​

  Protection- of delicate organs​

  Waterproofing- some animals secrete oils onto skin​

  Buoyancy- -lipids are less dense than water so floats, good for keeping animals ​afloat​
• lipids contain hydrogen, carbon and oxygen
• Because the proportion of oxygen to carbon and hydrogen is smaller than in carbohydrates. they have a much higher proportion of hydrogen than carbohydrate.​
• what is this

  A) triglycerides

  
• what is this

  A) phospholipid

  
• formation of triglyceride

  label

  A) glycerol

  B) 3 fatty acids

  C) condensation

  D) 3 h20

  E) triglycerides

  
• fatty acids

  • Fatty acids have an acidic head (COOH) which is polar.​
  • Fatty acids have a long chain of carbon and hydrogen atoms forming a hydrocarbon tail.​
  • Because the carbon-hydrogen bonds are nonpolar, the chain is hydrophobic, meaning they are not water soluble.​
  • In fatty acids hydrophobic long carbon chain dominates in chemical properties of the hydrophilic carboxyl group and gives the whole molecule hydrophobic cha
• saturated fatty acids

  no double bonds​

  between carbon atoms ​

  in hydrocarbon chain
• Mono-unsaturated fatty acid​

  One double bond​

  between carbon atoms ​

  in hydrocarbon chain
• Polyunsaturated fatty acid

  More than one double bond​

  between carbon atoms ​

  in hydrocarbon chain
• Animal lipids are often saturated (no double bonds) and occur as fats, whereas plant lipids are often unsaturated and occur as oils, such as olive oil and sunflower oil.