Proteins are large, complex molecules that re critical components of all tissues, including muscle, blood, and bone. Like carbohydrates and fat, they contain carbon, hydrogen, and oxygen. In contrast, however, the structure of proteins is dictated by DNA, and proteins contain nitrogen.
Amino acids are the building blocks of proteins; they are made up of a hydrogen atom, an acid group, an amine group containing nitrogen, and a unique side chain.
There are 20 amino acids in our bodies: 9 are essential amino acids, meaning that our bodies cannot produce them, and we must obtain them from food; and 11 are nonessential, meaning our bodies can make them, so they do not need to be consumed in the diet.