Carbohydrates

Edexcel AS-level BiologyBiological MoleculesLesson 2 of 25

Carbohydrates are organic compounds containing only carbon, hydrogen and oxygen. Hydrogen and oxygen are usually present in the same 2:1 ratio as in water, which gives the general formula

and the name, which means 'hydrated carbon'. For simple sugars x = y, so the formula is (CH₂O)_n. For example glucose, with n = 6, is C₆H₁₂O₆.

Key terms in this lesson

respiratory substrate

A molecule, such as glucose, that is broken down in respiration to release energy for the synthesis of ATP.

More in Biological Molecules

• Organic Compounds
• Monosaccharides
• Disaccharides
• Test for Sugars
• Polysaccharides
• Starch
• Test for Starch
• Glycogen

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