In this work, the spectrophotometric properties of amino acids and proteins are scientifically studied. First, general concepts regarding the biological significance of amino acids and proteins, as well as the main methods used in their analysis, are provided. The theoretical foundations of spectrophotometry—the interaction between electromagnetic radiation and molecules, the Bouguer-Lambert-Beer law, the molar absorption coefficient, and the UV (ultraviolet) absorption properties of amino acids—are highlighted. Furthermore, the spectral characteristics of aromatic amino acids (tryptophan, tyrosine, phenylalanine), the spectrophotometric analysis of proteins, and methods for determining their concentrations are analyzed. In the practical section, Olympiad problems, along with the capabilities, challenges, and limitations of the spectrophotometric method, are presented. At the end of the work, general conclusions and recommendations for future research are provided.