Organic Compounds

Edexcel AS-level BiologyBiological MoleculesLesson 1 of 25

Organic compounds are molecules built around a skeleton of carbon atoms, nearly always bonded to hydrogen. They are the molecules made by living things, which is where the name comes from. Simple carbon compounds such as carbon dioxide and carbonates are treated as inorganic.

Carbon is ideal as a skeleton because each carbon atom forms four covalent bonds. Carbon atoms can bond to each other to form long chains, branched chains and rings, and to other atoms such as oxygen, nitrogen and hydrogen. This allows an almost endless variety of stable molecules.

The four main groups of biological molecules are:

More in Biological Molecules

• Carbohydrates
• Monosaccharides
• Disaccharides
• Test for Sugars
• Polysaccharides
• Starch
• Test for Starch
• Glycogen

All 25 lessons in Biological Molecules · All Edexcel AS-level Biology topics