Topic 4 Proteins

Main source of nitrogen


  • Structural
  • Protective Enzymatic
  • Hormonal

They are made of amino acids, some of which are essential

Biological value: ability to contribute to tissue formation (nitrogen content)

High biological value or complete proteins are those containing all the essential amino acids.

Animal proteins Vegetable proteins
  • Meet
  • Egg
  • Milk and cheese
  • Fish
  • Legumes
  • Cereals
  • Seeds

Vegetable proteins have lower biological value: cereals have little lysine; corn lacks lysine and tryptophan; legumes have limited amounts of methionine. They can be completed by combination: ex. pasta + legumes.

Source: Freepik