So what exactly are amino acids and what are amino acids actually used for? Well, amino acids are these nitrogencontaining molecules, molecules that, as you may know, are the building blocks of protein. But we also use amino acids to actually synthesize other important molecules, such as nucleotide bases. And nucleotide bases are used to form DNA molecules, RNA molecules that are used to form ACP, the energy currency of the cell. So amino acids are very important molecules, and we also actually utilize amino acids for energy, as we'll see in electra to come. Now, what exactly are the sources of amino acids?