chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

, a Haworth projection is a common way of writing a

structural formula The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. The chemical bonding within the molecule is al ...

to represent the cyclic structure of

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 ...

s with a simple three-dimensional perspective. A Haworth projection approximates the shapes of the actual molecules better for furanoses—which are in reality nearly planar—than for pyranoses that exist in solution in the chair conformation.

Organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic matter, organic materials, i.e., matter in its various forms that contain ...

and especially

biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a ...

are the areas of chemistry that use the Haworth projection the most. The Haworth projection was named after the British chemist Sir

Norman Haworth Sir Walter Norman Haworth Fellow of the Royal Society, FRS (19 March 1883 – 19 March 1950) was a British chemist best known for his groundbreaking work on ascorbic acid (vitamin C) while working at the University of Birmingham. He received th ...

. A Haworth projection has the following characteristics: *

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 ...

is the implicit type of atom. In the example on the right, the atoms numbered from 1 to 6 are all carbon atoms. Carbon 1 is known as the

anomer In carbohydrate chemistry, a pair of anomers () is a pair of near-identical stereoisomers or diastereomers that differ at only the anomeric carbon, the carbon atom that bears the aldehyde or ketone functional group in the sugar's open-chain for ...

ic carbon. *

Hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

atoms on carbon are implicit. In the example, atoms 1 to 6 have extra hydrogen atoms not depicted. * A thicker line indicates atoms that are closer to the observer. In the example on the right, atoms 2 and 3 (and their corresponding OH groups) are the closest to the observer. Atoms 1 and 4 are further from the observer. Atom 5 and the other atoms are the furthest. *The groups below the plane of the ring in Haworth projections correspond to those on the right-hand side of a

Fischer projection In chemistry, the Fischer projection, devised by Emil Fischer in 1891, is a two-dimensional representation of a three-dimensional organic molecule by projection. Fischer projections were originally proposed for the depiction of carbohydrates a ...

. This rule does not apply to the groups on the two ring carbons bonded to the endocyclic oxygen atom combined with hydrogen.

References

Carbohydrate chemistry Carbohydrates Stereochemistry {{Stereochemistry-stub

See also

References