University:
The Pennsylvania State University
Course:
BMB 443W | Laboratory in Protein Purification and Enzymology
Academic year:

2024
Views:

113

Pages:

3
Author:

Alexis H.

Amino Amino acids, acids, peptides peptides and and proteins proteins An amino acid consists of a backbone, including an ammonium group, an alpha-carbon, and a carboxylate, as well as a variable side chain bonded to the alpha-carbon Amino acids are in an equilibrium between two acids with the proton (H+) moving between the amino group and the carbonyl group R-group or side chain Alpha carbon AN ch . Alpha-hydrogen c o Han ga In such an equilibrium, the weaker acid always predominates. As ammonia is a weaker acid than carboxylic acid, the equilibrium will lie to the left Amino acids are attached to other amino acids by covalent bonds, known as peptide bonds, which are formed by dehydration synthesis reactions By convention, peptide and protein structures are depicted with the amino acid whose amino group is free (the Nterminal end) on the left and the amino acid with a free carboxyl group (the C-terminal end) to the right Alpha amino group b Carboxyl group Proteins Primary structure: sequence of a chain of amino acids Secondary structure: local folding of the polypeptide chain into helices or sheets Tertiary structure: three-dimensional folding pattern of a protein due to side chain interactions Quaternary structure: protein consisting of more than one amino acid chain

Amino Acids, Peptides and Proteins