Carbohydrates

Carbohydrates are the most abundant organic compounds found in every living organism. They are also called saccharides, a name that comes from the Greek word 'sakcharon' meaning sugar, because a large number of them taste sweet. Structurally they are regarded as hydrates of carbon -- they contain hydrogen and oxygen in exactly the same 2:1 ratio as in water -- and the formal chemical definition used for them is that they are polyhydroxy aldehydes or polyhydroxy ketones, or compounds that yield such species on hydrolysis, with the general formula Cₙ(H₂O)ₙ. Familiar everyday examples span all three size classes: glucose is a monosaccharide (a single sugar unit that cannot be hydrolysed further), sucrose (ordinary table sugar) is a disaccharide built from two monosaccharide units, and starch is a polysaccharide built from thousands of glucose units strung together. …