Geometric Modelling and Analysis of the Amino Acid: Phenylalanine

L-phenylalanine (Phe), an essential amino acid, is necessary for the synthesis of proteins such as catecholamine and melanin, and is also the precursor of the amino acid L-tyrosine (Tyr). In this paper, optimized structures of Phe, were calculated by using semiempirical models such as AM1, PM3 and MNDO; Density Functional models (DFT) at B3LYP and Hartreefock methods (HF) with 6-311++G (d,p) level. The energies and geometric parameters of Kaempferol were also determined.