Arabinose is an

aldopentose In chemistry, a pentose is a monosaccharide (simple sugar) with five carbon atoms. The chemical formula of many pentoses is , and their molecular weight is 150.13 g/mol.monosaccharide Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. Chemically, monosaccharides are polyhy ...

containing five

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

atom Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished fr ...

s, and including an

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

(CHO)

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

Properties

For biosynthetic reasons, most saccharides are almost always more abundant in nature as the "D"-form, or structurally analogous to D-glyceraldehyde.The D/L nomenclature does not refer to the molecule's optical rotation properties but to its structural analogy to

glyceraldehyde Glyceraldehyde (glyceral) is a triose monosaccharide with chemical formula C3 H6 O3. It is the simplest of all common aldoses. It is a sweet, colorless, crystalline solid that is an intermediate compound in carbohydrate metabolism. The word comes ...

. However, L-arabinose is in fact more common than D-arabinose in nature and is found in nature as a component of biopolymers such as

hemicellulose A hemicellulose (also known as polyose) is one of a number of heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all embryophyte, terrestrial plant cell walls. Cellulose is crystalline, strong, an ...

and

pectin Pectin ( ': "congealed" and "curdled") is a heteropolysaccharide, a structural polymer contained in the primary lamella, in the middle lamella, and in the cell walls of terrestrial plants. The principal chemical component of pectin is galact ...

. The L-arabinose operon, also known as the araBAD operon, has been the subject of much biomolecular research. The

operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splic ...

directs the

catabolism Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipid ...

of arabinose in ''E. coli'', and it is dynamically activated in the presence of arabinose and the absence of glucose. A classic method for the organic synthesis of arabinose from glucose is the

Wohl degradation The Wohl degradation in carbohydrate chemistry is a chain contraction method for aldoses. The classic example is the conversion of glucose to arabinose as shown below. The reaction is named after the German chemist Alfred Wohl (1863–1939). L ...

. :

Etymology

Arabinose gets its name from

gum arabic Gum arabic (gum acacia, gum sudani, Senegal gum and by other names) () is a tree gum exuded by two species of '' Acacia sensu lato:'' '' Senegalia senegal,'' and '' Vachellia seyal.'' However, the term "gum arabic" does not indicate a partic ...

, from which it was first isolated.Merriam Webster Dictionary
/ref>

Use in foods

Originally commercialized as a sweetener, arabinose is an

inhibitor Inhibitor or inhibition may refer to: Biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotransmi ...

sucrase Sucrases are digestive enzymes that catalyze the hydrolysis of sucrose to its component monosaccharides, fructose and glucose. One form, sucrase-isomaltase, is secreted in the small intestine on the brush border. The enzyme invertase, which occurs ...

, the

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

that breaks down

sucrose Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refined ...

into

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

and

fructose Fructose (), or fruit sugar, is a Ketose, ketonic monosaccharide, simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and gal ...

in the

small intestine The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...

Notes

References

{{carbohydrates Aldopentoses Glycerols Furanoses Pyranoses

Properties

Etymology

Use in foods

See also

Notes

References