Amino acids are the building blocks of protein. You need protein in your diet to sustain your physiological processes. Without them, a your body, or any organism, cannot survive, so we need to make sure we get them in. Proteins consist out of two types of amino acids, essential and non essential amino acids. You can produce non essential amino acids in your body, so these do not need to be in your diet. On the other hand, essential amino needs to be present in your diet. So make sure you take enough essential amino acids, especially when you consume a plant based, or vegetarian diet.