peptide linkage
Học thuậtThân thiện
Definition
Noun The covalent chemical bond that connects the amino group (-NH₂) of one amino acid to the carboxyl group (-COOH) of another amino acid, releasing a molecule of water (H₂O) in the process. This bond is the fundamental linkage that forms the backbone of peptides and proteins.
Usage
The term "peptide linkage" is used specifically in biochemistry and molecular biology to describe the amide bond formed during protein synthesis. * The primary structure of a protein is defined by the sequence of amino acids joined by peptide linkages. * A peptide linkage is formed through a dehydration synthesis (condensation) reaction.
Examples
- The enzyme catalyzed the formation of a peptide linkage between the two amino acids.
- The rigidity of the peptide linkage influences the possible conformations of the protein chain.
- Hydrolysis breaks the peptide linkages in a protein, releasing the individual amino acids.
Advanced Usage
- Planar Structure: The peptide linkage has a partial double-bond character due to resonance, which forces the atoms involved (C, N, and the adjacent C and O) into a rigid, planar configuration.
- Dihedral Angles: The limited rotation around the bonds adjacent to the peptide linkage defines the phi (φ) and psi (ψ) angles, which are crucial for determining protein secondary structure.
Variants and Related Words
- Peptide Bond: A completely synonymous term used interchangeably with "peptide linkage."
- Amide Bond: A more general chemical term for the functional group (-CO-NH-); a peptide linkage is a specific type of amide bond found in biological molecules.
- Polypeptide: A chain of many amino acids linked by peptide linkages.
Synonyms
- Peptide bond
- Amide bond (in the specific biochemical context)
Related Phrases and Concepts
- Primary Structure: The linear sequence of amino acids in a polypeptide chain, held together by peptide linkages.
- Condensation Reaction: The type of chemical reaction that forms a peptide linkage, releasing water.
- Hydrolysis: The reaction that breaks a peptide linkage, using water.
Noun
- the primary linkage of all protein structures; the chemical bond between the carboxyl groups and amino groups that unites a peptide