Amino Acids
The generic structure of an
alpha amino acid in its un-ionized form.
Amino acids are biologically important organic compounds made from amine (-NH2)and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids. About 500 amino acids are known. Amino acids are the building blocks of proteins.
(http://en.wikipedia.org/wiki/Amino_acid)
(http://en.wikipedia.org/wiki/Amino_acid)
Polypeptides
A tetrapeptide (example Val-Gly-Ser-Ala) with
green marked amino end (L-Valine) and
blue marked carboxyl end (L-Alanine). http://en.wikipedia.org/wiki/Polypeptide
Polypeptides are linear organic polymers consisting of a large number of amino-acid residues
bonded together in a chain, forming part of (or the whole of) a protein molecule.Peptides are distinguished from proteins on the basis of size, and as a benchmark
can be understood to contain approximately 50 amino acids or less. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetrapeptides, etc. A polypeptide is a long, continuous, and unbranched peptide chain.
(http://en.wikipedia.org/wiki/Polypeptide)
bonded together in a chain, forming part of (or the whole of) a protein molecule.Peptides are distinguished from proteins on the basis of size, and as a benchmark
can be understood to contain approximately 50 amino acids or less. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetrapeptides, etc. A polypeptide is a long, continuous, and unbranched peptide chain.
(http://en.wikipedia.org/wiki/Polypeptide)
Proteins
A representation of the 3D structure of the protein myoglobin showing turquoise alpha helices. This protein was the first to have its structure solved by X-ray crystallography. Towards the right-center among the coils, a prosthetic group called a heme group (shown in gray) with a bound oxygen molecule (red). http://en.wikipedia.org/wiki/Protein
A protein is any of a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, esp. as structural components of body tissues such as muscle, hair, collagen, etc., and as enzymes and antibodies.
(http://en.wikipedia.org/wiki/Protein)