1. Food Nutrients
1) Carbohydrates- are made up of carbon, nitrogen and oxygen
They are energy giving foods( they are needed if your are very active)
Lack of carbs=lack of energy
They are made up of simple sugars: monosaccharide (e.g glucose & fructose)
Disaccharides (e.g sucrose & maltose)
Polysaccharides (e.g starch & cellulose)
Monosaccharide and most Disaccharide taste sweet, polysaccharides do
not. Monosaccharide and disaccharides are reducing sugars and when
tested with Benedict’s solution they give off a red precipitate.
Polysaccharides are non-reducing sugars Cellulose is also a carbohydrate
but it does not provide the body with nutrients, it is used as roughage
adding bulk to food so it passes out easier preventing constipation.
Excess carbs is converted into fats.
2) Proteins-are made up of carbon, hydrogen, oxygen, nitrogen and sometimes sulphur.
They are responsible for growth and repair
Repairs old tissues and makes new ones
Enzymes are protein molecules that speed up the rate of chemical reactions
They also make antibodies.
The base of a protein is called an amino acid, two amino acids form a dipeptide,
many amino acids form a polypeptide and large polypeptides are called proteins.
Proteins make up the most of the solid structures of the body e.g keratin in hair
and nails.
Lack of proteins leads to PEM (Protein Energy Malnutrition) e.g Marasmus
You test for a protein using a Biuret’s test
Excess amino acids are not stored but converted into glucose in the liver by a
process called deamination
3) Lipids- are insoluble in water they are made up of fatty acids and glycerol
The provide the body with a long term energy store
It is found around some vital organs for protections and under the skin for
insulation

2. 4) Vitamins and Minerals- are essential for alot of bodily processes but are only required in
small amounts each day
They can either be water-soluble (easily transported in blood) or fat-soluble
(absorbed from lipids). Vitamins cannot be stored and if unused they are excreted.
Sunlight reacts with fat under the skin to form vitamin B. Lack of vitamins lead to
deficiency diseases and lack of minerals lead to some sort of defiency
TABLES TO B SENT LATER>>>>>.
Malnutrition- occurs when a person does not receive sufficient amounts of each food group,
eating more of one does not compensate for eating less of another because each is required for a
specific task.
Metabolism- is all the chemical processes that occur in the body that are needed to maintain life.
FOOD ENERGY
Is the energy that is released from the food by the burning of oxygen. Burnt food produces water
and carbon dioxide when respiration occurs. The release of energy from food is respiration.
1gram of carbohydrate releases about 16kJ of energy
1 gram of lipids releases about 38 kJ of energy
1 gram of proteins releases about 17kJ of energy