1. What are carbohydrates?
2. Understanding simple carbohydrates.
3. Understanding complex carbohydrates.
4. What are the functions of carbohydrates?
5. What are the sources of carbohydrates?
Carbohydrates are macronutrients and are one of the three main ways by which our body obtains its energy. They are called carbohydrates as they comprise of carbon, hydrogen, and oxygen at their chemical level. Carbohydrates are essential nutrients which include sugars, fibers, and starches. They are found in grains, vegetables, fruits and in milk and other dairy products.
The food containing carbohydrates are converted into glucose or blood sugar during the process of digestion by the digestive system. Our body utilizes this sugar as a source of energy for the cells, organs, and tissues. The extra amount of energy or sugar is stored in our muscles and liver for further bodily needs.
The term ‘carbohydrate’ is derived from a French term ‘hydrate de carbone’ meaning ‘hydrate of carbon’.
The general formula of this class of organic compounds is Cn(H2O)n.
The carbohydrates are further classified into simple and complex which is mainly based on their chemical structure and degree of polymerization.
Simple carbohydrates (Monosaccharides and Disaccharides)
Simple carbohydrates have one or two sugar molecules. These include monosaccharides and disaccharides. In simple carbohydrates, molecules are digested and converted quickly resulting in a rise in blood sugar levels. They are abundantly found in milk products, beer, fruits, refined sugars, candies, etc. These carbohydrates are called empty calories, as they do not possess fiber, vitamins, and minerals.
Plants, being producers, synthesize glucose (C6H12O6) by using raw materials like carbon dioxide and water in the presence of sunlight. This process of photosynthesis converts solar energy to chemical energy. Consumers feed on plants and harvest energy stored in the bonds of the compounds synthesized by plants.
Monosaccharides
These are the simplest form of carbohydrate that cannot be hydrolyzed any further. They have the general formula of (CH2O)n. Some common examples are glucose, mannose, galactose, fructose, ribose, etc.
Disaccharides
Two monosaccharides combine to form a disaccharide. A disaccharide can have two units of the same or different monosaccharides. Examples of carbohydrates having two monomers include sucrose, lactose, maltose, etc. On hydrolysis, sucrose gives one molecule of glucose and fructose each; and maltose gives two molecules of only glucose.
Complex carbohydrates
Complex carbohydrates are chains of more than two sugar molecules. Complex carbohydrates, containing three or more monosaccharides bonded together, are divided into oligosaccharides, with three to ten monosaccharides, and polysaccharides, with greater than ten monosaccharides bonded together.
In complex carbohydrates, molecules are digested and converted slowly compared to simple carbohydrates. They are abundantly found in lentils, beans, peanuts, potatoes, peas, corn, whole-grain bread, cereals, etc. These carbohydrates are not sweet in taste and are also known as non-sugars. Complex carbohydrates have two main functions: storing energy and forming structures of living things.
Oligosaccharides
Carbohydrates that on hydrolysis yield two to ten smaller units or monosaccharides are oligosaccharides. They are further divided into various subcategories, for example:
Polysaccharides
They have ten or more monosaccharides bonded together. Polysaccharides are complex carbohydrates formed by the polymerization of a large number of monomers. For example, starch, glycogen, cellulose, etc. exhibit extensive branching and are homopolymers – made up of only glycogen units.
Starch is composed of two components – amylase and amylopectin. Amylose forms the linear chain and amylopectin is a much-branched chain.
Glycogen is called animal starch. It has a structure similar to starch but has more extensive branching.
Cellulose is a structural carbohydrate and is the main structural component of the plant cell wall. It is a fibrous polysaccharide with high tensile strength. In contrast, to starch and glycogen, cellulose forms a linear polymer.
The main function of carbohydrates is to provide energy and food to the body and to the nervous system.
Carbohydrates are known as one of the basic components of food including sugars, starch, and fiber which are abundantly found in grains, fruits, and milk products.
Carbohydrates are also known as starch, simple sugars, complex carbohydrates and so on.
They are also involved in fat metabolism and prevent ketosis.
They inhibit the breakdown of proteins for energy as they are the primary source of energy.
An enzyme by name amylase assists in the breakdown of starch into glucose, finally to produce energy for metabolism.
1. Simple sugars are found in the form of fructose in many fruits.
2. Galactose is present in all dairy products.
3. Lactose is abundantly found in milk and other dairy products.
4. Maltose is present in cereal, beer, potatoes processed cheese, pasta, etc.
5. Sucrose is naturally obtained from sugar and honey containing small amounts of vitamins and minerals.
These simple sugars that consist of minerals and vitamins exist commonly in milk, fruits, and vegetables.
Many refined and other processed foods like white flour, white rice, and sugar lack important nutrients and hence, they are labeled “enriched”.
It is quite healthy to use vitamins, carbohydrates and all other organic nutrients in their normal forms.
