Page 23 - Science Class 06
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our diet (or food) comes from carbohydrates
present in it. For a normal person, about
400-500 gram of carbohydrate is required
daily. A growing child, a nursing mother or a
sportsman, however, need more carbo- Rice Potato Wheat
hydrate than a cellulose, which forms the Cellulose
cell wall of plants, is also a carbohydrate,
It is also a complex form
but is not a food. This is because cellulose
of carbohydrates. It is
cannot be digested or absorbed in the body.
obtained from roughage.
When eaten, however, cellulose acts as a Man cannot digest
cellulose.
roughage and help in keeping the intes nal
tract in good working order that is, cellulose
helps in the maintaining healthy diges ve Aim : To test for the presence of starch in
system. For example, sugar is a type of food items.
carbohydrate which is sweet in taste. There Procedure : Take a small quan ty of
are two kinds of sugar— simple sugar and boiled rice. Put it into a plate and crush it
compound sugar. with a spoon. Now, add one drop of
Carbohydrates are found in three forms: iodine solu on to it.
Observe the colour of the rice. If its
1. Sugar 2. Starch
colour changes into deep blue, it means
3. Cellulose
that rice contains starch. Repeat this
Sugar experiment with other food items. If the
Sugar is the simplest form of carbohydrates. colour does not changes, it means those
food items do not have starch.
The main sources of sugar are glucose
sugarcane, jaggery and fruits.
Aim : To test for the presence of sugar in
food items.
Procedure : Take a small quan ty of a
food item in a beaker and crush it with a
spoon. Pour one litre of water into the
beaker. Now, add 2-3 drops of Benedict’s
Sugar Glucose Fruits
solu on to it and heat the solu on for
Starch 5-10 minutes. If red precipitate is
obtained, then it means that the sample
Starch is a complex form of carbohydrates.
of food contains sugar. If no precipitate is
Important sources of starch are rice, wheat
obtained, then it means the sample of
maize, potatoes, etc.
food does not contain sugar.
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