Carbohydrates are polyhydroxy aldehydes, ketones, alcohols, acids, their simple derivatives and their polymers having linkages of the acetal type.
Carbohydrates are synthesized by plants during photosynthesis. This is the process of trapping energy from sunlight with the aid of chlorophyll.
The name carbohydrate was first used in 1844 by Schmidt, but the sweet nature of sugar had already recognized for many centuries. It was said that sugar was extracted as early as 3000 BC in India.
Carbohydrate in the form of glucose serves as the most basic energy source for all cells in the body. Foods high in carbohydrates include breads, pastas, potatoes, rice and fruits. Legumes also a good source of carbohydrates.
Foods with a predominantly carbohydrate content are important because they form the basis of most diets, especially for poorer people in the developing world.
Carbohydrates are one of the four major classes of biomolecules and play several important roles in all life forms, including:
*The principle function of carbohydrates in human nutrition is the maintenance of the blood glucose and then absorbed into the blood stream.
*Sources of metabolic fuels and energy stores
*Parts of RNA and DNA in which ribose and deoxyribose, respectively are linked by N-glycosidic bonds to purine and pyrimidine bases
*Integral features of many proteins and lipids (glycoproteins and glycolipids), especially in cell membranes \
*It is the components o major dietary fibers.
Food sources and roles of carbohydrate
