Proteins are organic polymers made up of chains of amino acids and are a crucial material in many biological functions (Reece and others 2011). There are twenty basic amino acids, eight of which are essential to the adult human diet and must be consumed rather than synthesized in the body. These essential amino acids are isoleucine, leucine, tryptophan, lysine, valine, phenylalanine, methionine and threonine, with an additional requirement for histidine in children's diets (Potter and Hotchkiss, 1995). Non-essential amino acids can be synthesized from these, and all amino acids are used as monomers to build proteins that perform many important functions in the body (Reece et al., 2011). Most amino acids exist as isomers and are given a designation depending on whether they are isomers or not. rotating a plane of polarized light to the right or left, called dextrorotatory “D” or levorotatory “L” isomers, respectively (Al-Holy and Rasco 2007). It should be noted that only L amino acids are used in protein synthesis (Weber and Miller 1981). The biological functions of proteins include increasing the rate of biochemical reactions in the form of enzymes, moving important substances to where they are needed in the form of transport proteins, regulating the body in the form of hormones, allowing the body to moving in the form of contractile proteins and providing support in the form of structural proteins (Reece and others 2011). Additionally, proteins have a lot of functionality in foods, including providing essential amino acids as well as energy, viscosity, texture, water-holding capacity, foaming and emulsifying properties and by allowing gel formation (Culbertson 2007). As mentioned above, the essential amino acids provided by the...... middle of paper ...... p.Reece JB, Urry LA, Cain ML, Wasserman SA, Minorsky PV, Jackson RB. 2011. Campbell Biology. 9th ed. San Francisco: Cummings-Pearson. 1263 p.Siegwein AM, Vodovotz Y, Fisher EL. 2011. Concentration of soy protein isolate affects texture, sensory and storage properties of starch-based confectioneries. J Food Sci 76:E422-8. Sorgentini DA, Wagner JR, Anon MC. 1995. Effects of heat treatment of soy protein isolate on the characteristics and structure-function relationship of soluble and insoluble fractions. J Agric Food Chem 43:2471-9.Thompson LD, Dinh T. 2009. Food protein isolation and thermal stability. FDSC 4303/5303 Food Chemistry Laboratory Manual. Lubbock, Texas: Texas Tech University, Department of Animal and Food Sciences. Weber AL, Miller SL. 1981. Reasons for the appearance of the twenty protein-coded amino acids. J Molecular Evolution 17:273-84.