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2 The organic substances

A component is said to be organic when its molecules contain the carbon atom C and the
hydrogen atom H. Other organic molecules contain C, H and oxygen O, nitrogen (N) and
2–
phosphorus (P). Carbon dioxide CO and the carbonates (CO ) are part of the mineral
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substances.
Examples of organic molecules: Carbohydrates, lipids, proteins and vitamins.

A- Carbohydrates (energetic food)

Carbohydrates are energetic substances. They are represented by the simple sugars, the
disaccharides and the polysaccharides.
b- The disaccharides
xa- The simple sugars or monosaccharides
They are made up of two simple sugars.
The simple sugars are called “fast” sugars Sucrose + Water Glucose + Fructose
such as glucose found in the grapes, fructose

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Maltose obtained from the transformation of
found in the fruits and honey. They all have starch:
the same chemical formula C H O . Maltose + Water Glucose + Glucose
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Lactose or milk sugar:
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Lactose + Water Glucose + Galactose
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c- Complex sugars or polysaccharides Galactose or simple sugar is obtained by the
digestion of milk.
The complex sugars or “slow” sugars such as
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starch found in all grains (rice, wheat) and in food
that derive from grains. The food contains other
polysaccharides such as glycogen in meat and
cellulose in the fruits and vegetables. All
polysaccharides have the same general formula:
(C H O ) .
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