Function of Carbohydrates

  • substrate for respiration to provide energy for cell activities(immediate source of energy)
  • Formation of nucleic acids - DNA
  • form supporting structures - cell walls in plants
  • converted to other organic compounds like proteins and fats
  • synthesize lubricants mucus which is made up of a carbohydrate and a protein
  • synthesize nectar in some flowers

Functions of Proteins

  • Synthesis of new cytoplasm for growth and repair of worn out body cells
  • Synthesizes enzymes and some hormones
  • formation of antibodies to combat diseases*

Functions of Fats

  • source and long term storage form of energy
    • suitable for long term storage as fats have higher energy value compared to proteins and carbohydrates (2 times more)
  • Insulating materials that reduce excessive heat loss
    • animals, example seal have a thick layer of fat beneath their skin called blubber to reduce loss of body heat
  • Solvent for fat soluble vitamins and other vital substances like hormones
  • essential part of cells, especially cell membranes
  • way to reduce water loss from skin surface; glands in skin secrete an oily substance
    • oily substance forms a thin layer over the skin surface reduce water loss by evaporation
    • Oily substance also reduces rate of heat loss from the skin