Protein

Functions:
1. Source of amino acids for various productive processes e.g. growth, repair and
turnover of tissues
2. Secondary source of energy (when tissue protein is being mobilised in starvation)

Amino acids:
Amino acids are the building blocks of protein (what protein is made up of)
Amino aids are…

Animal Foods Vegetable proteins

Good sources of indispensable amino acids Poor sources of indispensable amino acids
i.e. have all the necessary amino acids. i.e. are missing one or more amino acids
Sources: eggs, meat, fish, milk and Soya (limiting amino acids)
beans Sources: rice, peas, wheat, corn and
HBV gelatine…

2. Formation of enzymes:

These facilitate most of the chemical reactions in the body e.g. digestion of nutrients.



3. Production of hormones:

E.g. Vasopressin is a hormone responsible to control blood pressure (protein is needed to
produce this hormone)



4. Immunity:

Plays a key role in the immune system; if…

Protein forms the major components of the hair and nails as well as the structural
framework of the bones



Sources of protein



HBV LBV

Egg Rice
Meat Corn
Fish Wheat
Milk Peas
Soya bean (only plant source) Gelatine (only animal source)



Different foods contain different proteins: each with a unique…

Cheap source of HBV protein
NSP- prevents bowel disorder and contributes to healthy blood cholesterol
Source of isoflavones- helps to prevent cancer and CHD (type of anti-oxidant)
Good source of iron



2. Tofu

Tofu is produced from ground soya beans, which has been sieved. The proteins
coagulate, producing soft cheese…

In fevers and wasting diseases the body is in negative nitrogen balance (output exceeds
input)

Healthy adults excrete the same amount as ingested (nitrogen equilibrium)