Hi, I'm Robin Higgins. And this is introduction to enzyme and co-enzyme activity. Alright, so let's review enzymes first. So, an enzyme's main role is to lower the activation energy. So, if we have a reaction that turns some chemical from A to B, there is going to be an activation energy or a barrier before you can do that. And usually means putting energy in. And so, sometimes this peak, the activation abbreviated EA, is so high, that it would happen very slowly or not all. Unless we could have a catalyst or an enzyme that comes and it makes the peak a lot shorter. So, an enzyme now will help lower the activation energies that this transformation from a to B can happen. Alright so, that's the basic enzyme chemistry. But what about co-enzymes? Well, co-enzymes are actually under this umbrella term which is co-factors. And so, inside co-factors, you have both co-enzymes and you also have this thing called prosthetic groups. And so, both the co-enzymes and prosthetic groups are non-protein molecules that bind with the enzyme to make it function. So, basically we've got both of them are molecules, not proteins and they are essential to functionality. So, not every enzyme has a co-factor but if it does have a co-factor, that it needs to function. And the difference between co-enzymes and prosthetic groups, are that co-enzymes are loosely bound and prosthetic groups are tightly bound. Alright, so really common co-factors are often actually vitamins. And vitamins are just these molecules that make sure the enzyme works correctly. So that circle is to bind with the enzyme and it will allow this to happen, it'll allow the enzyme to lower the activation energy. They're kind of like assistants to the enzymes, except they're very, very essential assistants. So this is a really codependent that couldn't function without its little helper. Alright, I'm Robin Higgins and this is what is basic enzyme and co-enzyme chemistry.