A long chain of amino acids make up a protein. After the protein has been digested, the amino acids are still present in your body. These acids help break down food. But that's not all they do. Antibodies are made up of amino acids and therefore, amino acids are natural immune boosters. They also assist in muscle building and repairing body tissue.
Essential Amino Acids
There are 20 amino acids. Our bodies naturally make 12 and eight 'essential amino acids' come from our diets. By eating a plant based diet balanced with grains, nuts, seeds, beans, and legumes you can easily get all the essential amino acids your body needs. Think of amino acids as a pair with protein - if you're getting your daily intake of protein, you'll be getting your intake of amino acids.
Complete Protein vs. Incomplete Protein
There is also a difference in 'complete' proteins versus 'incomplete' proteins. A complete protein means that all eight essential amino acids are present in the same proportion. In the plant world, only quinoa and soybeans have equal proportions of the eight essential amino acids. Other vegetables, fruits, legumes, and grains have those eight amino acids, but in different ratios - making them incomplete. However, our bodies are smart, if we eat a wide variety of those foods, during digestion, our bodies can piece together those eight essential amino acids so we get the protein we need.
Lastly, you can get some amino acids from Liquid Aminos - I was very hesitant about this at first, but they basically are a liquid protein concentrate made from soybeans. It takes like soy sauce and I've actually grown to like it better than soy sauce (to me it tastes much less salty that even low sodium soy sauce). Bragg's makes a great product you can find at most grocery stores and following this Amazon link.