peptide bond(redirected from Protein backbone)
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the linkage between atoms or radicals of a chemical compound, or the symbol representing this linkage and indicating the number and attachment of the valencies of an atom in constitutional formulas, represented by a pair of dots or a line between atoms, e.g., H—O—H, H—C≡C—H or H:O:H, H:C:::C:H.
coordinate covalent bond a covalent bond in which one of the bonded atoms furnishes both of the shared electrons.
covalent bond a chemical bond between two atoms or radicals formed by the sharing of a pair (single bond), two pairs (double bond), or three pairs of electrons (triple bond).
disulfide bond a strong covalent bond, —S—S—, important in linking polypeptide chains in proteins, the linkage arising as a result of the oxidation of the sulfhydryl (SH) groups of two molecules of cysteine.
high-energy phosphate bond an energy-rich phosphate linkage present in adenosine triphosphate (ATP), phosphocreatine, and certain other biological molecules. On hydrolysis at pH 7 it yields about 8000 calories per mole, in contrast to the 3000 calories yielded by phosphate esters. The bond stores energy that is used to drive biochemical processes, such as the synthesis of macromolecules, contraction of muscles, and the production of the electrical potentials for nerve conduction.
high-energy sulfur bond an energy-rich sulfur linkage, the most important of which occurs in the acetyl-CoA molecule, the main source of energy in fatty acid biosynthesis.
hydrogen bond a weak, primarily electrostatic, bond between a hydrogen atom bound to a highly electronegative element (such as oxygen or nitrogen) in a given molecule, or part of a molecule, and a second highly electronegative atom in another molecule or in a different part of the same molecule.
ionic bond a chemical bond in which electrons are transferred from one atom to another so that one bears a positive and the other a negative charge, the attraction between these opposite charges forming the bond.
peptide bond the —CO—NH— linkage formed between the carboxyl group of one amino acid and the amino group of another; it is an amide linkage joining amino acids to form peptides.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
the common link (-CO-NH-) between amino acids in proteins, actually a substituted amide, formed by elimination of H2O between the -COOH of one amino acid and the H2N- of another. Compare: eupeptide bond, isopeptide bond.
Farlex Partner Medical Dictionary © Farlex 2012
The chemical bond between carboxyl groups and amino groups of neighboring amino acids, forming an amide group and constituting the primary linkage of all protein structures.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
pep·tide bond(pep'tīd bond)
The common link (-CO-NH-) between amino acids in proteins, formed by elimination of H2O between the -COOH of one amino acid and the H2N- of another.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
peptide bondA covalent bond formed between amino acids during protein synthesis. The OH- on a carbon atom links with the H- on a nitrogen atom to form a water molecule which is given off as each peptide bond is formed. Amino acids linked by peptide bonds form dipeptides, tripeptides or polypeptides.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
peptide bonda covalent C arbon-N itrogen bond that joins the carboxyl group of one AMINO ACID to the amino group of another (with loss of a water molecule). See Fig. 249 . Many amino acids are joined by peptide bonds to form a POLYPEPTIDE CHAIN.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005
pep·tide bond(pep'tīd bond)
The common link (-CO-NH-) between amino acids in proteins.
Medical Dictionary for the Dental Professions © Farlex 2012