And now the reaction can take place at a relatively high rate. Now, two examples of aspartate proteases that we're going to focus on in future lectures is Renmin, and this is basically the enzyme that is used to control blood pressure as well as pepsin. And this is one of the digestive enzymes that is found in our digestive system. And finally, let's take a look at metalloprotiases. So, just like the name implies, this has to do with the fact that inside the active side of metalloproteases, we actually have a metal atom, and usually the metal atom is zinc. So what's the point of the metal atom?