Molecule Tutorials - Herong's Tutorial Examples - v1.26, by Herong Yang
Peptide, Peptide Bond, Amino Acid Residues
This section provides a quick introduction of peptide, which a chain of two or more amino acid residues linked together by peptide bonds.
What Is Peptide? - A peptide is a chain of two or more amino acid residues linked together by peptide bonds. A peptide is a polymer, because it consists entirely of a number of similar units, amino acid residues, bonded together.
What Is Condensation Reaction of Amino Acids A condensation reaction of amino acids is a chemical reaction between two acid reacts. During the condensation reaction, the carboxyl group an amino acid reacts to the amino group of another amino acid to form a new covalent bond between the carbon atom and the nitrogen atom. A water molecule is formed at the same time. See the diagram below (source: philpoteducation.com):
What Is Peptide Bond? - A peptide bond is the covalent bond between the carbon atom and the nitrogen atom resulted from a condensation reaction between two amino acids.
What Is Amino Acid Residue? - An amino acid residue is the remaining structure of an amino acid after a condensation reaction with another amino acid.
The term "peptide" can have a prefix to refer to the number of amino acid residues in the peptide, like:
Dipeptide: consists of two amino acid residues Tripeptide: has three amino acid residues Tetrapeptide: has four amino acid residues Pentapeptide: has five amino acid residues Hexapeptide: has six amino acid residues ...
A protein is actually a large peptide, usually has 20 or more amino acid residues. But a peptide may not be a protein, see the next section.
Table of Contents
Molecule Names and Identifications
►Peptide, Peptide Bond, Amino Acid Residues
Protein Visualization - Ribbon Diagram
Composed Proteins or Protein Complexes
wwpdb.org - Worldwide PDB (Protein Data Bank)
Nucleobase, Nucleoside, Nucleotide, DNA and RNA
ChEMBL Database - European Molecular Biology Laboratory
PubChem Database - National Library of Medicine
INSDC (International Nucleotide Sequence Database Collaboration)
HGNC (HUGO Gene Nomenclature Committee)