.3 Metabolism

• Metabolism includes:

  conversion of glucose to starch, glycogen and cellulose

  the formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids

  the use of glucose and nitrate ions to form amino acids which in turn are used to synthesise proteins

  respiration

  breakdown of excess proteins to form urea for excretion.
• Metabolism is the sum of all the reactions in a cell or the body.
• The energy transferred by respiration in cells is used by the organism for the continual enzyme controlled processes of metabolism that synthesise new molecules.