The variations in the physical characteristics between different proteins are influenced by the overall amino acid compositions, but even more important is the unique amino acid

Sequence

Explanation:

Physical properties of the proteins are foundation of biological function of them.

A protein molecule is made up from the long chain of the amino acids. Each amino acid is linked to its neighbor by covalent peptide bond. Thus, proteins are also called as polypeptides.

Each protein has unique sequence of the amino acids, exactly same from one molecule to next. Different proteins has its own particular sequence of amino acid. This sequence is responsible for folding and binding of the protein and also its physical characteristics.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.