What are Carbohydrates?

Our bodies are like plants that process chemicals. When absorbed through various types of reactions, the chemicals are dispersed through the human body in order to be immediately used or "stocked" for use when needed. Two broad categories are distinguished with regard to the chemicals used by the body. The substances that we need to consume more often and in large amounts will be referred to as called macronutrients, while the micronutrients include only those substances that need to be absorbed in small amounts. For the living organisms, there are only 3 macronutrient classes known to be essential: carbohydrates, proteins, and fats.

It is known that the main sources of energy for the human body are carbohydrates. In the body, carbon, oxygen, and hydrogen represent carbohydrates that are bonded in the following ratio: Cx(H2O)y. The whole numbers y and x differ and depend on the carbohydrates discussed above. In order to release the energy, the animals break down the carbohydrates during the metabolism process. By eating various foods, the animals obtain carbohydrates. Examples of such foods are rice, breads, potatoes, and so on. Photosynthesis is the process by which plants manufacture the carbohydrates. Energy is harvested from sunlight so that the reaction takes place.

A primary system for storing chemicals is, for example, the potato. It contains the glucose molecules which are manufactured during the photosynthesis. The glucose molecules in a potato are bound together and form a long chain. Apart from the simple sugars, there are carbohydrates that form long chains of sugars. These are the complex carbohydrates.

Units of sugars combine in order to form carbohydrates, also known as saccharide units. The monosaccharides, containing only one unit of sugar and the disaccharides, known to have two units of sugar, are simple sugars. They taste sweet and are easy to break down so that energy is released by the body. Monosaccharides, considered as most common, are the fructose and the glucose. The basic form of sugar that the body stores for energy is the glucose. In most fruits, the main sugar source is the fructose. Both sugars, however, share the same formula - C6H12O6 . Their structures differ. Two sugar units are bonded together in the disaccharides.

The simple sugars' polymers are the complex carbohydrates. Bonded together, simple sugar units, containing long chains, form the complex carbohydrates. This is the reason why they are called polysaccharides. A complex carbohydrate, called starch, is contained in the potato, as mentioned earlier. The plants use the principle polysaccharide starch for storing glucose, later to be used as an energy source. Various specialized organs or seeds are used by the plants to preserve starch.


Examples of common starch sources are beans, rice, corn, wheat, potatoes, and other foods. When starch is consumed by humans, the enzyme amylase, included in the intestines and the saliva, destroys the bonds connecting the repeating units of glucose. This makes it possible for the sugars to find their way to the bloodstream. The glucose is then distributed to the areas in need of energy or the body stores it as glycogen. This is yet another glucose polymer, the polysaccharide, which the animals use for energy storing. The glucose in excess, when bound together, forms glycogen molecules which are stored by animals in the muscles and the liver tissue as a source of energy ready to be released in an instance. Glycogen and starch are both glucose polymers. However, whereas glycogen is a chain of glucose units that is branched, starch has a straight and long chain of units.

Cellulose is also an important polysaccharide and a third monosaccharide glucose polymer. Because of the fact that a two-dimensional structure is formed by the units of glucose, cellulose is different from the glycogen and the starch. It is also known as plant fiber and humans are unable to digest it. This is the reason that it is not absorbed into the body when it makes its way through the digestive tract. Termites and cows, for example, have digestive tracts containing bacteria that are capable of digesting cellulose. Being a stiff material, it is used by the plants as a structural molecule, adding support to the stem, leaves, and other parts of the plant.