Everything around you is made of building blocks—food, computers, phones… the list goes on. Your body is no exception; it is made up of complex molecules and compounds that form cellular structures like bones, muscles, hair, and nails. One key type of compound in your body is protein, but what exactly are proteins, and how do they create such intricate structures?
Proteins are macromolecules, meaning they are large molecules made up of smaller units called amino acids. There are hundreds of amino acids in a single protein, and they help the protein carry out its functions. Some proteins give your body structure, like collagen in your bones, while others help transport essential molecules, such as oxygen.
The versatility of proteins comes from the structure of their amino acids. Each amino acid has three parts that play important roles in building and shaping the protein. Two of these parts, called the amine group and carboxyl group, can link together to form a chain, like beads on a string. This bond between two amino acids is known as a peptide bond. When many of these bonds form, they create a protein.
Several amino acids joined together
The third part of each amino acid is called the side chain, and this is what gives each amino acid its unique properties. Some side chains repel water (hydrophobic), while others attract it (hydrophilic). This mix of side chains allows proteins to fold into specific shapes, and the way a protein folds determines its function. The body uses 20 different amino acids, each with a unique side chain, to create a wide variety of proteins. The order and combination of these 20 amino acids are what make one protein different from another.
From a dietary perspective, amino acids are divided into two categories: essential and non-essential. There are nine essential amino acids, which our bodies cannot produce, so we must get them from our diet. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The remaining 11 are non-essential because our bodies can produce them, although they are still necessary for good health. But where do we get these essential amino acids from?
