Carbohydrates:
Carbohydrates are compounds of elements carbon, hydrogen and oxygen. It is also known as hydrated carbon because in its ratio of hydrogen and oxygen atom is like the ratio in water. (Glucose is a carbohydrate which chemical formula is C6H12O6. Where ratio of H:O is 12:6 or 2:1 which is like the ratio of H:O in H2O that is 2:1).
There are many types of carbohydrates. The main carbohydrates found in our food are in the form of starch and sugars. Glucose which is also known as instant energy provider is also a carbohydrate. Starch is made by adding many glucose molecules together through chemical bond.
Some Other Examples of Carbohydrates:
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- Fructose is one of the carbohydrates which is present in the fruit.
- Sucrose (table sugar) is made by one molecule of glucose and one molecule of fructose.
- Lactose is present in the milk. It is also called milk sugar.
Sources of Carbohydrates:
Potato, sweat potato, sugarcane, papaya, melon, mango, maize, rice, wheat, bajra etc.
Test for Presence of Starch in food:
Required materials: – dropper, food items to be tested (potato) and knife.
Required chemicals: – iodine solution
Procedure: –
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- Take a fresh potato and wash it with water.
- Cut the potato by using knife.
- Put 2-3 drops of iodine solution on it with the help of dropper.
- Observe the change occurring.
Observation: – A blue-black colour appear on potato where iodine solution dropped.
Result: – Appearance of blue-black colour indicates presence of the starch in potato.
Importance of the carbohydrate:
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- Carbohydrate is the primary fuel for the livings. Energy is released due to oxidation of glucose molecules in presence of oxygen inside the cell. This energy is used in various activities.
- Carbohydrate is also a component of the cell membrane. Many fibers we use in our daily life are made of carbohydrates.
- Plants store food in the form of starch which is a carbohydrate.
- Carbohydrates are also part of genetic materials i.e., DNA and RNA.