Fischer projection
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In chemistry (particularly organic chemistry and biochemistry), a Fischer projection is a two-dimensional representation of a three-dimensional organic molecule by projection. All bonds are depicted as horizontal or vertical lines. The carbon chain is depicted vertically, with carbon atoms represented by the center of crossing lines. The orientation of the carbon chain is so that the C1 carbon is at the top.
In a Fischer projection, all horizontal bonds project forward (out of the page or screen). Therefore, a Fischer projection cannot be rotated by (2n+1)×90° in the plane of the page or the screen, as the orientation of bonds relative to one another can change, converting a molecule to its enantiomer.
Fischer projections are most commonly used in biochemistry to represent monosaccharides, but can also be used for amino acids or for other organic molecules. Since Fischer projections depict the stereochemistry (three-dimensional structure) of a molecule, Fischer projections are very useful for differentiating between enantiomers of chiral molecules. A computational approach to determining the chirality of a molecule based on computing the sign of a determinant is given by Cieplak and Wisniewski .
The Fischer projection was invented by Emil Fischer.
[edit] See also
[edit] References
- ↑ Cieplak, T. and J.L. Wisniewski (2001) A New Effective Algorithm for the Unambiguous Identification of the Stereochemical Characteristics of Compounds During Their Registration in Databases. Molecules 6:915-926. Online Article