2.3  Carbohydrates and Lipids

big ninja

Essential Idea:

Compounds of carbon, hydrogen and oxygen

are used to supply and store energy


  • Monosaccharide monomers are linked together by condensation reactions to form disaccharides and polysaccharide polymers
  • Fatty acids can be saturated, monounsaturated or polyunsaturated
  • Unsaturated fatty acids can be cis or trans isomers
  • Triglycerides are formed by condensation from three fatty acids and one glycerol


  • Structure and function of cellulose and starch in plants and glycogen in humans
  • Scientific evidence for health risks of trans fats and saturated fatty acids
  • Lipids are more suitable for long-term energy storage in humans than carbohydrates
  • Evaluation of evidence and the methods used to obtain the evidence for health claims made about lipids


  • Use of molecular visualisation software to compare cellulose, starch and glycogen
  • Determination of body mass index by calculation or use of a nomogram