Common properties of protein

Proteins play a fundamental role not only in sustaining life, but also foods derived from plants and animals. Proteins exhibit a number of common properties that just be accounted for in any definition of these compounds:

*There are polymeric of high molecular weight, which are built up by the linking together of a large number of small molecules.

*They are amphoteric, i.e., they being able to act as an acid or a base. This enables them to resist small changes in pH. 

*Following complete hydrolysis of a protein, the hydrolysate consists entirely of amino acids (except that additional groups, such as heme, iron, copper, may also be found in the case of a conjugate protein). It is commonly recognized that amino acids being linked by peptide bonds formed between α-amino and α-carboxylic acid groups of neighboring amino acids in the polypeptide sequence.

*In their polymeric structures, the amino acid units of proteins are joined together in definite sequences and exist in definite three-dimensional conformations. This sequence built from a limited number of well-defined building blocks, the 20 genetically determined amino acids and a smaller number of posttranslational modifications of them.
Common properties of protein