Amino acids are the fundamental building blocks of proteins and play a central role in nearly every biological process. Each amino acid consists of a core structure containing an amino group, a carboxyl group, and a unique side chain that determines its properties and function. There are 20 standard amino acids that combine in various sequences to form proteins, which in turn support the body’s structural framework, enzyme systems, and cellular functions. Among these, essential amino acids cannot be synthesized by the body and must be obtained through diet, while non-essential amino acids can be produced internally. Amino acids are critical for muscle growth, tissue repair, immune function, and metabolic regulation. They also contribute to neurotransmitter synthesis, energy production, and hormone balance. In nutrition and wellness applications, amino acids are commonly used in sports supplements, clinical nutrition, and functional foods due to their rapid absorption and targeted physiological benefits.