Amino acid synthesis is the process by which cells create amino acids, the building blocks of proteins. This process can occur through two main pathways: the transamination pathway, where an amino group is transferred from one molecule to another, and the de novo synthesis pathway, where simple organic compounds are converted into amino acids. In living organisms, amino acids can be classified as essential or non-essential. Essential amino acids must be obtained from the diet, while non-essential amino acids can be synthesized by the body. Proteins, enzymes, and metabolism play crucial roles in these synthesis pathways.