peptides are complex molecules that do all kinds of jobs in your body. They make up your hair, nails and bones, give tissues and organs their shape, and help your muscles contract. Proteins are also involved in the immune system, transporting chemicals throughout the body, and synthesizing DNA, which contains our genetic code.
Each protein has a specific three-dimensional (3D) structure determined by the sequence of amino acids, which are linked together in chains. A change in this amino acid sequence can alter the protein’s function and mode of action.
A molecule of an amino acid contains hydrogen, carbon and nitrogen, with the carboxyl group (-COOH) attaching to another amino acid forming a covalent bond. The resulting chain of amino acids, called a polypeptide, can twist to form protein shapes.
The primary functions of proteins are structural support, storage of other molecules, chemical reaction facilitators, and chemical messengers. Proteins also play a role in storing energy and providing fuel for the cells of your body.
When you are undergoing intense exercise, protein is essential to the repair and recovery of muscle tissue. However, it’s important to remember that protein is not your body’s first choice for energy, which should come from carbohydrates and fats.
The best sources of protein are meat, poultry, fish, soy products, dairy and some whole grains. Plant foods that are rich in protein include beans, lentils, peas (green, lima, pinto, split), chickpeas/garbanzos, edamame and soy products (tofu, tempeh). When choosing these plant-based proteins it is important to choose those with a high digestible essential amino acid score.