Question

Why do we get instant energy from glucose?

Answer 1

Hint: Monosaccharides are the simplest form of sugar, which does not need any further digestion. Chemically these are formed of C, H, and O, generally in the ratio of $1:2:1$. The general formula of monosaccharide is $C_{n}H_{2}O_{n}$. Where n is the number of carbon atoms.

Complete answer:
Glucose is a type of Monosaccharide and is the simplest sugar, which can be readily absorbed by the body. Unlike any other carbohydrates, glucose does not have to be processed by the digestive system for energy. The body can easily absorb this kind of sugar molecule. Once inside, glucose undergoes the oxidation process, which results in the release of ATP, a high-energy molecule that provides energy for the cell.
- Types of monosaccharides based on the number of carbon atoms:
1. Trioses: molecules containing 3-C atoms, for example, Glyceraldehyde.
2. Tetroses: molecules containing 4-C atoms, for example, Erythrose.
3. Pentoses: molecules containing 5-C atoms, for example, Ribose.
4. Hexoses: molecules containing 6-C atoms, for example, Glucose.
5. Heptoses: molecules containing 7-C atoms, for example, Sedoheptulose.
- Types of monosaccharides based on nature of the carbonyl ($C=O$) group:
1. Aldoses: They have aldehyde ($-CHO$) group at the first carbon of the molecule, for example, Glucose, Galactose.
2. Ketose: They have a ketonic ($RC=OR'$) group at the second carbon of the molecule, for example, Fructose.

Note: Glucose is present abundantly in the body fuel. It is also known as the carbohydrate currency of the body. The physiological fuel value of glucose is 4.0 Kcal. Glucose provides energy for about 60% of the energy needs of an adult. One glucose molecule produces about 38 ATP molecules (i.e., 280 Kcal).