What are they made of?

Carbohydrates are made up of long chains of simple sugars like glucose. They are stored in the liver as glycogen or converted to fats.
Fats are made up of 3 fatty acids linked to a molecule of glycerol. They can be stored under the skin and around organs as adipose tissue.
Proteins are made up of amino acids. There are 22 amino acids. They don't get stored.

Some amino acids can't be made by the body so it is obtained from a diet - these are called essential amino acids.
Animal proteins (found in meat) contain all essential amino acids - plant proteins don't.
This means that vegetarians need to eat a wide variety of plant sources to make sure they have a complete range of amino acids in their diet.

Animal proteins - first class proteins
Plant proteins - second class proteins

	Created by Carina C over 8 years ago

GCSE Biology (Module B1: Understanding Organisms) Note on B1b: Human health and diet, created by Carina C on 28/03/2016.