Proteins Flashcards
What are the functions of protein in the body?
Used for growth, especially in children and pregnant women
Used to repair body tissue
Enzymes vital for metabolism are composed of proteins
Hormones, which regulate important bodily functions, are also composed of proteins
Proteins provide a secondary source of energy. When the body has used all the amino acids it needs, the remainder are ‘burnt’ for energy
How many amino acids are there?
22 amino acids
How many essential amino acids are there?
8 amino acids are essential for adults
10 amino acids are essential for children
What are high biological value foods?
Foods which contain all the essential amino acids such as animal tissue or soya bean, except from gelatine
What are low biological value foods?
Foods which lack one or more essential amino acid such as plant sources other than soya bean
What is complementation?
This is when you eat a meal consisting of one high biological value food combined with a low biological value food e.g. toast with beans
Vegetable sources of protein:
Soya beans and soya products
Pulses and beans
Cereal grains and cereal products
Nuts
Animal sources of protein:
All meats such as poultry, offal and game Fish Cheese Milk Eggs Gelatine
What source of protein has a high biological value?
Most animal sources
What source of protein has a low biological value?
Most plant sources
Effects of deficiency of protein:
In children, growth slows down or stops
Digestive upsets are caused as enzymes are not produced
The liver fails to function normally
Muscles become weak, so limbs are thin and the tummy is soft and may look distended
Effects of excess protein
Weight gain as they may be stored as fat
Intestinal irritation as too much may cause diarrhoea or constipation
