Polypeptides
Polypeptides are chains of amino acids. Proteins are made up of one or more polypeptide molecules.
polypeptide
a molecule consisting of many joined amino acids, but not as complex as a protein
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby ...
Over the last few years, it has been clearly established that normal plasma contains low levels of oxidized polypeptides, and that these accumulate in tissues during several age-related pathologies.
Polypeptide: A molecule made up of a stri ng of amino acids. A protein is an example of a polypeptide.
Proteins: The active molecules in all cells. Proteins control biochemical reactions and determine the physical structure of organisms.
polypeptide chain - a chain of peptides or amino acids. A polypeptide chain usually consists of 100 or fewer amino acids. A protein is made up of one or several polypeptide chains. [Source: BioTech's Life Science Dictionary] ...
Polypeptide chain The chain of aminoacids joined by peptide bonds which is the primary product of the translation of the mRNA of a gene.
Polyploid Having more than the normal two haploid sets of chromosomes.
Polypeptide (protein). A polymer composed of multiple amino acid units linked by peptide bonds.
Polyploid. A multiple of the haploid chromosome number that results from chromosome replication without nuclear division.
Polypeptide a chain of amino acids bonded together
(poly = many; pepti = digested‚ cooked) ...
Polypeptides
Two or more amino acids bonded together are called a peptide. A chain of many amino acids is referred to as a polypeptide. The complete product, either one or more chains of amino acids, is called a protein.
Polypeptide A series of amino acids, each connected to the next in the series by a peptide bond.
[edit] Polypeptides
The convention for a polypeptide is to list its constituent amino acid residues as they occur from the amino terminus to the carboxylic acid terminus. The amino acid residues are always joined by peptide bonds.
Polypeptide
A long chain of amino acids joined by peptide bonds. Cf. peptide.
Related Terms:
Amino acid
Any of a class of 20 molecules that are combined to form proteins in living things.
Polypeptide
Peptide containing more than approximately 20 'peptide linked' amino acid residues.
Polypeptides (neuropeptides):
Bombesin/GRP:
bombesin
gastrin releasing peptide (GRP) ...
Polypeptide is the name given to a chain of amino acids synthesized from one mRNA. The term polypeptide refers to the fact that amino acids are linked by what is called a peptide bond and, of course, poly means many.
POLYPEPTIDE - See PEPTIDE.
pre-mRNA - An RNA molecule which is transcribed from chromosomal DNA in the nucleus of eukaryotic cells, ...
a polypeptide hormone (3485 D) secreted by the cells of the islets Of Langerhans in response to a fall in blood sugar levels. Induces hyperglycaemia.
A polypeptide 10 amino acids long is split into various smaller fragments, and the amino acid sequences of some of the fragments are determined.
protein - polypeptide chain which serves a structural or enzymatic role or other role in the cell.
replicated chromosomes - chromosomes which have undergone DNA replication and contain two sister chromatids.
A polypeptide secreted by bacteria which inhibit or prevent the growth of related bacteria which lack the corresponding colicin immunity proteins. Colicins are encoded by a group of naturally occurring plasmids first found in E. coli (e.g.
"one gene one polypeptide hypothesis" A revision of the one gene, one enzyme hypothesis.
A DNA sequence that codes for a specific polypeptide; a gene. See DNA, Gene. Clone. An exact genetic replica of a specific gene or an entire organism. See Cloning. Cloning.
in the transcript of a gene and survives processing of the RNA in the cell nucleus to become part of a spliced messenger of a structural RNA in the cell cytoplasm; an exon specifies the amino acid sequence of a portion of the complete polypeptide.
N- or C-terminal The amino acids which form polypeptides are joined by peptide bonds between the amino group of one amino acid and the carboxy group of the next.
While determining the polypeptide sequence resulting from gene translation is straightforward, determining the actual three-dimensional (3D) structure requires some sophisticated experimental techniques.
The secondary structure is the tendency of the polypeptide to coil or pleat due to H-bonding between R-groups. The tertiary structure is controlled by bonding (or in some cases repulsion) between R-groups.
When viral RNA is translated into a polypeptide sequence, that sequence is assembled in a long chain that includes several individual proteins (reverse transcriptase, protease, integrase).
This helical, usually right-handed arrangement of a polypeptide chain is a common secondary structure in proteins. The helix has maximal intra-chain hydrogen bonding.
Related Terms:
Polypeptide
A long chain of amino acids joined by peptide bonds.
Proteins consist of one or more chains of amino acids called polypeptides. The sequence of the amino acid chain causes the polypeptide to fold into a shape that is biologically active. The amino acid sequences of proteins are encoded in the genes.
The basic building block of proteins (or polypeptides). Containing a basic amino (NH2) group, an acidic carboxyl (COOH) group and a side chain (R - of a number of different kinds) attached to an alpha carbon atom. Thus:
List of amino acids
Name ...
A stretch of amino acids on polypeptides that targets proteins to specific destinations in eukaryotic cells.
signal-transduction pathway
A mechanism linking a mechanical or chemical stimulus to a cellular response.
- The process of biosynthesis of a polypeptide chain using genetic instructions from the mRNA
Transposon
- A mobile genetic element that can move from one location in the gene and reinsert at another site.
"Blueprint" for protein synthesis that is transcribed from one strand of the DNA (gene) and which is translated at the ribosome into a polypeptide sequence.
the oxygen carrying molecule of red blood cells; it is made up of four polypeptide chains (2 alpha type and 2 beta type) and non-protein molecules called porphyrins
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition.
Insulin (a small protein having two polypeptide chains) and immunoglobulin molecules, for example, have interchain and intrachain disulfide bonds. Endothelin and HLA molecules also have disulfide bonds.
translation - process whereby mRNA code is used by the ribosome to synthesize a polypeptide chain (protein) from amino acid precursors.
transposable element - see transposon ...
disulfide bond - covalent intrachain bonds found in protein molecules; covalent linking of two -SH groups of neighboring cysteine residues in a folded polypeptide chain. These bonds are rarely, if ever found in the cytosol.
There are 20 amino acids in nature from which all proteins are built. Polymers constructed by two or more amino acids, joined by peptide bonds, are called polypeptides.
A single ribosome in a eukaryotic cell can add 2 amino acids to a protein chain every second. In prokaryotes, ribosomes can work even faster, adding about 20 amino acids to a polypeptide every second.
 See also: Polyp, Protein, Peptide, Proteins, Trans
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