Carbohydrate

A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula C m (H 2 O) n (where m may be different from n).

Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone.

This formula holds true for monosaccharides.

Monosaccharides (from Greek monos: single, sacchar: sugar), also called simple sugar, are the simplest form of sugar and the most basic units of carbohydrates.

The term is most common in biochemistry, where it is a synonym of saccharide, a group that includes sugars, starch, and cellulose.

Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food.

The term is most common in biochemistry, where it is a synonym of saccharide, a group that includes sugars, starch, and cellulose. Polysaccharides serve for the storage of energy (e.g. starch and glycogen) and as structural components (e.g. cellulose in plants and chitin in arthropods).

Starch or amylum is a polymeric carbohydrate produced by most green plants as energy storage.

The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides.

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages, and on hydrolysis by amylase enzymes give the constituent monosaccharides or oligosaccharides.

The term is most common in biochemistry, where it is a synonym of saccharide, a group that includes sugars, starch, and cellulose.

Much of biochemistry deals with the structures, functions and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates and lipids, which provide the structure of cells and perform many of the functions associated with life.

The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides.

An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/ ; from the Greek ὀλίγος olígos, "a few", and σάκχαρ sácchar, "sugar") is a saccharide polymer containing a small number (typically three to ten ) of monosaccharides (simple sugars).

While the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose, as in the monosaccharides fructose (fruit sugar) and glucose (starch sugar) and the disaccharides sucrose (cane or beet sugar) and lactose (milk sugar).

Glucose is the most abundant monosaccharide, a subcategory of carbohydrates.

The 5-carbon monosaccharide ribose is an important component of coenzymes (e.g. ATP, FAD and NAD) and the backbone of the genetic molecule known as RNA.

Ribose is a naturally-occurring carbohydrate with the formula C 5 H 10 O 5 ; specifically, it is a pentose monosaccharide (simple sugar) with linear form H−(C=O)−(CHOH) 4 −H, which has all the hydroxyl groups on the same side in the Fischer projection.

The saccharides are divided into four chemical groups: monosaccharides, disaccharides, oligosaccharides, and polysaccharides.

Disaccharides are one of the four chemical groupings of carbohydrates (monosaccharides, disaccharides, oligosaccharides, and polysaccharides).

Some exceptions exist; for example, deoxyribose, a sugar component of DNA, has the empirical formula C 5 H 10 O 4.

The backbone of the DNA strand is made from alternating phosphate and sugar residues.

A carbohydrate is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula C m (H 2 O) n (where m may be different from n).

Biomolecules include large macromolecules (or polyanions) such as proteins, carbohydrates, lipids, and nucleic acids, as well as small molecules such as primary metabolites, secondary metabolites, and natural products.

While the scientific nomenclature of carbohydrates is complex, the names of the monosaccharides and disaccharides very often end in the suffix -ose, as in the monosaccharides fructose (fruit sugar) and glucose (starch sugar) and the disaccharides sucrose (cane or beet sugar) and lactose (milk sugar).

Like other carbohydrates, it combusts to carbon dioxide and water.

The 5-carbon monosaccharide ribose is an important component of coenzymes (e.g. ATP, FAD and NAD) and the backbone of the genetic molecule known as RNA.

RNA and DNA are nucleic acids, and, along with lipids, proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life.

Other polysaccharides contained in dietary fiber include resistant starch and inulin, which feed some bacteria in the microbiota of the large intestine, and are metabolized by these bacteria to yield short-chain fatty acids.

The three main purposes of metabolism are: the conversion of food to energy to run cellular processes; the conversion of food/fuel to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of nitrogenous wastes.

The carbohydrates are technically hydrates of carbon; structurally it is more accurate to view them as aldoses and ketoses.

Glucose, C 6 H 12 O 6, was originally thought of as C 6 (H 2 O) 6 and described as a carbohydrate.

This includes chemical compounds such as acetic or lactic acid, which are not normally considered carbohydrates.

When bound to coenzyme A, it is central to the metabolism of carbohydrates and fats.

It also includes dietary fiber which is a carbohydrate but which does not contribute much in the way of food energy (kilocalories), even though it is often included in the calculation of total food energy just as though it were a sugar.

Foods are composed chiefly of carbohydrates, fats, proteins, water, vitamins, and minerals.

It is abundant in cereals (wheat, maize, rice), potatoes, and processed food based on cereal flour, such as bread, pizza or pasta.

Flour contains a high proportion of starches, which are a subset of complex carbohydrates also known as polysaccharides.

Trehalose, a major sugar of insects, is rapidly hydrolyzed into two glucose molecules to support continuous flight.

Trehalose is a sugar consisting of two molecules of glucose.

Galactose, a component of milk sugar lactose, is found in galactolipids in plant cell membranes and in glycoproteins in many tissues.

Galactose (, galacto- + -ose, "milk sugar") sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose.

Polysaccharides serve for the storage of energy (e.g. starch and glycogen) and as structural components (e.g. cellulose in plants and chitin in arthropods).

Energy is thus often said to be stored by cells in the structures of molecules of substances such as carbohydrates (including sugars), lipids, and proteins, which release energy when reacted with oxygen in respiration.

This includes chemical compounds such as acetic or lactic acid, which are not normally considered carbohydrates.

In industry, lactic acid fermentation is performed by lactic acid bacteria, which convert simple carbohydrates such as glucose, sucrose, or galactose to lactic acid.

Polysaccharides serve for the storage of energy (e.g. starch and glycogen) and as structural components (e.g. cellulose in plants and chitin in arthropods).

As a meal containing carbohydrates or protein is eaten and digested, blood glucose levels rise, and the pancreas secretes insulin.

Monosaccharides are the simplest carbohydrates in that they cannot be hydrolyzed to smaller carbohydrates.

When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g. sucrose being broken down into glucose and fructose), this is recognized as saccharification.