Chapter 7: Human Nutrition
Year 10 Food Technology
1
Sources of Protein
Storage of Proteins
• Amino acids can not be stored
• Liver removes their amino group and
changes it to glycogen
ENERGY produced ----- 17 kilojoules/ g of
protein
Composition of
Proteins
Amino
Acids
Oxygen
Made of amino
acids (building
blocks of all
proteins)
Nitrogen
Functions of Protein
.
Needed for building
• Build cells and tissues e.g skin,
muscles, blood etc. (Carbohydrates
and fat can not do this)
• Growth and tissue repair
• Needed to make enzymes and
hormones
5
Vitamins
Features
vitamins share

A. Not digested or broken down for
energy

B. Not built into the body structure

Needed in small amounts by body

Work in association with enzymes during
chemical reactions in the body
Classes of Vitamins
Water
Soluble ( Mostly
found in green veg, fruits,
cereals)
Fat soluble ( mostly found in
animal fat and vegetables
oils)

Vitamin
Vitamin C
Vit D
Function
sources
Prevents scurvy Orange, lemon ,
disease (poor fibre tomatoes , potatoes
formation in blood
carrying tissues
leads to gums and
skin bleeding)
Prevents Rickets
(poor absorption and
deposition of calcium
in bones)
Butter, milk, cheese,
egg yolk, fish, when
skin exposed to
sunlight vit D
produced When
exposed to sunlight,
the skin can make
vitamin D when
When exposed to
Scurvy