Search results
Results from the WOW.Com Content Network
Codon–amino acids mappings may be the biological information system at the primordial origin of life on Earth. [122] While amino acids and consequently simple peptides must have formed under different experimentally probed geochemical scenarios, the transition from an abiotic world to the first life forms is to a large extent still unresolved ...
By convention, a chain under 30 amino acids is often identified as a peptide, rather than a protein. [1] To be able to perform their biological function, proteins fold into one or more specific spatial conformations driven by a number of non-covalent interactions , such as hydrogen bonding , ionic interactions , Van der Waals forces , and ...
Amino acid biosynthesis is the set of biochemical processes (metabolic pathways) by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to synthesize all amino acids. For example, humans can synthesize 11 of the 20 standard amino acids ...
The amino acids in a polypeptide chain are linked by peptide bonds between amino and carboxyl group. An individual amino acid in a chain is called a residue, and the linked series of carbon, nitrogen, and oxygen atoms are known as the main chain or protein backbone.
The different amino acids are identified by the functional group. As a result of the three different groups attached to the α-carbon, amino acids are asymmetrical molecules. For all standard amino acids, except glycine, the α-carbon is a chiral center. In the case of glycine, the α-carbon has two hydrogen atoms, thus adding symmetry to this ...
Amino acids that must be obtained from the diet are called essential amino acids. Eukaryotes can synthesize some of the amino acids from other substrates . Consequently, only a subset of the amino acids used in protein synthesis are essential nutrients .
Some amino acids have functions by themselves or in a modified form; for instance, glutamate functions as an important neurotransmitter. Amino acids can be joined via a peptide bond . In this dehydration synthesis, a water molecule is removed and the peptide bond connects the nitrogen of one amino acid's amino group to the carbon of the other's ...
There, most of the peptides are broken into single amino acids. Absorption of the amino acids and their derivatives into which dietary protein is degraded is done by the gastrointestinal tract. The absorption rates of individual amino acids are highly dependent on the protein source; for example, the digestibilities of many amino acids in ...