• Most of the molecules in living organisms fall into three categories:?carbohydrates, proteins and lipids
• These?all contain carbon?and so are described as organic molecules

Chemical Elements Table

Carbohydrates

• Long chains of?simple sugars
• Glucose?is a simple sugar ( a monosaccharide)
• When?2 glucose molecules join together maltose is formed?(a disaccharide)
• When?lots?of glucose molecules join together?starch, glycogen or cellulose?can form (a polysaccharide)

Glycogen, cellulose and starch are all made from glucose molecules

Fats

• Most fats (lipids) in the body are made up of?triglycerides
• Their basic unit is?1 glycerol molecule chemically bonded to 3 fatty acid chains
• The fatty acids vary in size and structure
• Lipids are divided into?fats?(solids at room temperature) and?oils?(liquids at room temperature)

Structure of a triglyceride

Proteins

• Long chains of?amino acids
• There are about 20 different amino acids
• They all contain the?same basic structure?but the?‘R’ group is different for each one
• When amino acids are joined together a protein is formed
• The amino acids can be arranged in any order, resulting in hundreds of thousands of different proteins
• Even a small difference in the order of the amino acids results in a different protein being formed

General amino acid structure

Amino acids join together to form proteins

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