Amino acids are very small bio molecules with all average molecular weight of about 135 daltons. Proteins are polymers of amino acids. Amino acids are important and they can be classified into three groups; polar, non polar and charged. Amino acids have salt like character. For athletes or anyone who practices regular strenuous physical activity, IsoLeucine supplements are recommended. Although there are foods that contain this amino acid, people who are extremely active and exercise heavily need more IsoLeucine in their bodies to repair and protect muscle tissues. Internal pressure in a liquid system is measure of intermolecular cohesive forces and confirms the presence of solute –solvent interactions. The density and speed of L-iso in aqueous concentrated NaBr, NaCl, KBr (5%, 10%, 15%) at T= 303K have been measured. These parameters are used to calculate the internal pressure (pi). Here the KBr aqueous solution having very high solute solvent interaction than the NaBr and NaCl aqueous solution, because K+ ion is a structure breaking ion which interact to the end group of the amino acid (COO-) Hence it is found that the present study shows there is variation in the internal pressure of the three halides
