Answer
When essential amino acids such as phenylalanine are not synthesized, cells obtain them through catabolic pathways that break down proteins into those essential amino acids. Therefore, diet also plays a major role because the amount and type of protein consumed affect the amount of phenylalanine in the body.
Work Step by Step
Catabolic reactions convert complex molecules into simpler, easily absorbable constituents. Phenylalanine is an amino acid that is not synthesized by the human body. However, it is present in protein-containing food items. When such food is consumed, the enzymes in the body break down the protein into amino acid monomers, including phenylalanine.
