Valine is an aliphatic amino acid that is closely related to leucine and isoleucine both in structure and function. These amino acids are extremely hydrophobic and are almost always found in the interior of proteins. They are also seldom useful in routine biochemical reactions, but are relegated to the duty of determining the three-dimensional structure of proteins due to their hydrophobic nature. They are also essential amino acids and must be obtained in the diet. Important sources of valine include soy flour, cottage cheese, fish, meats, and vegetables. Valine is incorporated into proteins and enzymes at the molar rate of 6.9 percent when compared to the other amino acids.