The carbohydrates, carbohydrates or carbohydrates are biomolecules composed of carbon, hydrogen and oxygen. Carbohydrates are part of the bodies of living beings fulfilling structural and energy storage functions. For example: ribose, sucrose, raffinose, starch.
By consuming them in food, offer a readily available source of energy (unlike fats, which also contain energy but require a longer process in the body to obtain it). The process by which a carbohydrate molecule releases its energy is called oxidation.
Each gram of carbohydrate contributes 4 kilocalories.
Types of Carbohydrates
According to their structure, carbohydrates are classified into:
- Monosaccharides. Formed by a single molecule.
- Disaccharides. Formed by two monosaccharide molecules, joined by a covalent bond (glycosidic bond).
- Oligosaccharides. Made up of between three and nine monosaccharide molecules. They are usually bound to proteins, so they form glycoproteins.
- Polysaccharides. Formed by chains of ten or more monosaccharides. The chains may or may not be branched. In organisms, they fulfill structure and storage functions.
Examples of monosaccharides
- Arabinose. He is not free in nature.
- Ribose. Is found in:
- Cow liver
- Pork loin
- Unpasteurized milk
- Fructose. Is found in:
- Glucose. It is essential for good physical and mental functioning. Is found in:
- Dairy products
- Galactose. It is not in a natural state.
- Mannose. In food, it is found in legumes.
- Xylose. It is difficult to digest, it is found in the following foods:
- Corn husks
Examples of disaccharides
- Saccharose. Composed of one molecule of glucose and one of fructose. It is the most abundant disaccharide. In food, it is found in:
- Sweet industrial drinks
- Lactose. Composed of a molecule of galactose and a molecule of glucose. In food, it is found in:
- Other dairy
- Maltose. Formed by two glucose molecules. It is the least common disaccharide in nature, but it is formed industrially. In food, it is found in:
- Cellobiose. Formed by two glucose molecules. It does not exist as such in nature.
Examples of oligosaccharides
- Raffinose. Is found in:
- Beet stalks
- Melicitous. Composed of one molecule of fructose and two of glucose. In food, it is found in:
Examples of polysaccharides
- Starch. It is found in plants because it is the way they store monosaccharides. In food, they are found in:
- Glycogen. It is stored in muscles and liver to give energy. In food it is found in:
- Cellulose. It is a structural polysaccharide, it is found in the cell wall mainly of plants, but also of other organisms. It is what in food we call “fiber”:
- Whole grains
- Chitin. Similar in structure to cellulose, but with nitrogen in its molecule, which makes it more resistant. It is used as a food stabilizer.