Amino acids are essential for the synthesis of proteins. Proteins are composed of chains of amino acids, which are linked together through peptide bonds to form a unique three-dimensional structure. These proteins play crucial roles in the body, such as enzymes that catalyze biochemical reactions, antibodies that help defend against pathogens, and structural components in cells and tissues. Amino acids are obtained through the diet and are also synthesized by the body. They can be categorized as essential amino acids (which must be obtained from the diet) and non-essential amino acids (which can be synthesized by the body). While amino acids are important for protein synthesis, they are not directly involved in the synthesis of alkaloids, lipids, or carbohydrates.