Side Chain

In organic chemistry and biochemistry, a side chain is a chemical group that is attached to a core part of the molecule called "main chain" or backbone. The placeholder R is often used as a generic placeholder for alkyl (saturated hydrocarbon) group side chains in chemical structure diagrams. To indicate other non-carbon groups in structure diagrams, X, Y, or Z is often used. The R, historically, was introduced by 19th-century French chemist Charles Frédéric Gerhardt and may be derived from radical, or from residue and its German equivalent Rest.

In polymer science, the side chain or pendant chain is oligomeric or polymeric offshoot extends from the backbone chain of a polymer. Side chains have noteworthy influence on a polymer's properties, mainly its crystallinity and density. An oligomeric branch may be termed a short-chain branch and a polymeric branch may be termed a long-chain branch. Side groups are different from side chains; they are neither oligomeric nor polymeric.

In proteins (composed of amino acids) the side chains are attached to the alpha-carbon atoms of the amide backbone.

Other articles related to "chain, side chain, side chains":

Conformational Entropy
... Conformational entropy is the entropy associated with the physical arrangement of a polymer chain that assumes a compact or globular state in solution ... In proteins, backbone dihedral angles and side chain rotamers are commonly used as descriptors, and in RNA the base pairing pattern is used ... In particular, the conformational entropy of the amino acid side chains in a protein is thought to be a major contributor to the energetic stabilization of the denatured state and thus a barrier to protein folding ...
Polycarboxylate Ether Superplasticizer - Chemical Structure
... PCEs are composed by a methoxy-polyethylene glycol copolymer (side chain) grafted with methacrylic acid copolymer (main chain) ... of electron cloud, which gives a chemical polarity to the side chains ... The number and the length of side chains are flexible parameters that are easy to change ...
Marker Degradation - Route From Diosgenin
... heavily on kinetic control to degrade the sapogenin side chain while leaving similar functional groups on the steroid nucleus (relatively) unaffected ... that the sapogenins had a ketone spiro acetal structure in their side chain ... This forms the acetyl side chain of progesterone and an esterified hydroxyl group on the steroid nucleus The ester is then hydrolyzed under strongly basic conditions ...
L-isoaspartyl Methyltransferase - Function
... groups from S-adenosyl-L-methionine to the alpha side chain carboxyl groups of damaged L-isoaspartyl and D-aspartatyl amino acids ... The enzyme takes the end methyl residue from the methionine side chain and adds it to the side chain carboxyl group of L-isoaspartate or D-aspartate to create a methyl ...

Famous quotes containing the words chain and/or side:

    Oft, in the stilly night, Ere Slumber’s chain has bound me, Fond Memory brings the light Of other days around me.
    Thomas Moore (1779–1852)

    The most interesting thing which I heard of, in this township of Hull, was an unfailing spring, whose locality was pointed out to me on the side of a distant hill, as I was panting along the shore, though I did not visit it. Perhaps, if I should go through Rome, it would be some spring on the Capitoline Hill I should remember the longest.
    Henry David Thoreau (1817–1862)