Cofactor

in this video, we're going to begin our discussion on co factors. So it turns out that the catalytic activity of men the enzymes is actually dependent on the presence of relatively small molecules called co factors. And so what are co factors? Well, it turns out that co factors air just non protein portions of an enzyme, and they are in some way and somehow involved with proper enzyme catalysis. And so that brings us to two important terms that you guys need to be familiar with when it comes to co factors. And the first is an app oh, enzyme, and the second is a hollow enzyme. And so apple enzymes are enzymes that are inactive. And that's because this is the enzyme without its co factor. And so because it doesn't have its co factor, Apple enzymes don't work now. On the other hand, hollow enzymes are enzymes that are catalytic lee active, and that's because this is the enzyme with its co factor. And so this hollow enzyme actually does work and so down below. In our example image, I'll share with you guys something that helps me distinguish between apple enzymes and hollow enzymes. But first, I want you guys to know that co factors tend to bind to the active sites of enzymes. But the functional roles that co factors actually have varies greatly from enzyme toe enzyme. And we'll be able to talk about that in more depth when we talk about different types of enzyme catalysis later in our course now down below. In our example image notice in our central blue box here that this blue structure here represents an enzyme. And so when the enzyme is not bound to its co factor, which is this red dot right here notice that the enzyme is referred to as an app Oh, enzyme and the app Oh, enzyme is inactive, meaning it does not work. And again, that's because it's not bound to its co factor, which is the red dot Now, when the co factor bind to the app Oh, enzyme, it becomes a hollow enzyme and so you can see that the co factor tends to bind to the active site of the enzyme, which is this, uh, shape, um, right here. And so the hollow enzyme is actually an active form of the enzyme, and so something that helps me distinguish between app Oh, enzymes and hollow enzymes is that I know that app Oh, enzymes are always trying to apologize. And so here we have a signed and it's saying I apologize. And the reason that AP oh, enzymes are always trying to apologize is because they are always in active. They are always saying I'm inactive right now. And so the reason that they are inactive is again because they are not bound to their co factor. Now, on the other hand, holla enzymes are enzymes that we know are active. And so, if you need an active enzyme, all you need to do is holla at your boy and your boy is holla enzyme. And so holla enzymes always like. If you need an active enzyme, all you gotta do is holla at me. And so hopefully that'll help you guys remember that holla enzymes are the active version of the enzyme that air bound to the co factor. And so that concludes our lesson on the introduction to co factors. And I'll see you guys in our next video

So now that we've introduced co factors in this video, we're going to talk about how co factors can be broken up into two main groups. The first are co enzymes, and the second are metal ions. And so co enzymes are small organic molecules that are derived from vitamins, and so these include both prosthetic groups and co substrates. And so we've mentioned prosthetic groups in some of our previous lesson videos and so recall that these are tightly bound or co Vaillant Lea attached CO enzymes, whereas co substrates, on the other hand, are loosely bound. And these are recyclable substrate. Co enzymes and so really co substrates are very similar to substrates because they are both taken by the enzyme and chemically converted into something different. And so really, the main difference between a normal substrate and a co substrate is that co substrates are recyclable, meaning that after their utilized by an enzyme, they're quickly regenerated back into their normal state. And so examples of co substrates include both 80 p and n a. D. H. And so we know that a teepee can be utilized by an enzyme as a form of energy, and it can be converted into a D P, which has one less phosphate group. And we know from our previous bio courses that there are many processes out there that allow for the regeneration of a teepee, converting ADP back into a teepee. And so because a teepee is recyclable in this fashion, it can be quickly regenerated. It's considered a coast substrate, and for similar logic, N a. D H is also a co substrate. So now moving on to our second main group of co factors we have the metal ions and metal ions are pretty much exactly what they sound like. They are metal atoms with a net charge and, just like co enzymes can be further broken up into prosthetic groups and co substrates. Metal ions can be further broken up into metallic oh enzymes and activator ions. And so Metallica enzymes are comparable to prosthetic groups because they are both tightly bound and so Motala enzymes are enzymes with tightly bound metal ions. Now, activator ions are comparable to co substrates because they are both loosely bound and so activator ions are loosely bound metal ions. And it turns out that the trend the Potala Oh enzymes tend to be transition metals such as iron, copper, zinc and manganese, whereas the activator ions, on the other hand, tend to be alkali and alkaline Earth metals such as sodium, potassium, magnesium and calcium, and so down below notice that we have these two different charts that are color coded. We have this blue chart, which are all of our co enzymes, and we have the yellow chart, which are are metal ions and these air certainly not all of the co enzymes that exist. This is just a small portion of relevant co enzymes that we're going to encounter moving forward. But for now, I definitely do not expect you guys to memorize all of these co enzymes and all of these metal ions. I just want to show you guys some examples of co enzymes and metal ions. And so one thing that I really want you guys to note is that this coenzyme chart on the left has an entire additional column that the metal ion chart does not have. And that is the vitamin precursor. And so that's really important to note that co enzymes are derived from vitamins and so you can see that we have vitamin B seven, b five, b two, B three and B six here, and notice that all of these vitamins also have alternative names. And so that's something important to keep in mind Moving forward. Now again, we're going to talk about each of these enzymes co enzymes in more detail as we move forward in our course and encounter enzymes that utilize thes co enzymes. For instance, we know that biotin is a prosthetic group of an enzyme piru car box lace, which is very important for a process known as glue Coney O Genesis, Which again we're going to talk a lot more about later in our course and eso essentially what we have are we have a bunch of prosthetic groups and really the on Lee Cho substrates that are in this list are coenzyme a here and uh, this right here. These are, uh, the on Lee Cho substrates. The others in the list are cove are prosthetic groups. And so over here on the right notice, we have the metal ions and remember the metallic Oh ions tend to be transition metals, whereas activator ions tend to be alkali earth and alkali metals. And so, essentially, what you'll notice is that the on Lima tallow enzymes that we have listed here are the mag unease here, and that is it. And so again, moving forward, we're gonna talk a lot more about different co enzymes and metal ions. But this concludes our lesson, and I'll see you guys in our next video.