Types of Enzymes

in this video, we're going to begin our discussion on the different types of enzymes. So it turns out that there are six major classes of enzymes and most enzymes fall under one of these six major classes. And so the six major classes of enzymes are Oxydol. Reductase is transfer races, hydro laces, I som races, laces and like cases. And so moving forward in our course, we're going to briefly talk about each one of these major classes of enzymes in their own separate videos because most of your professors expect you guys to recognize the different reactions that these enzymes catalyze. And so one way that helps me remember all of these six major classes of enzymes is to remember that they all help reactions get over the hill where each of these red letters in over the hill represents the first letter of one of the major classes of enzymes. And so down below we have a little energy diagram, one that we've seen before, and our previous lesson videos just to remind us that enzymes literally help reactions get over the hill. And so the hill here is literally the energy of activation and all of these enzymes do this in part by stabilizing the transition state and so moving forward in our next lesson video. We're going to talk about our first. The major class of ends on the Oxydol reductase is so I'll see you guys in that video.

So in our last lesson video, we said that there are six major classes of enzymes, and the pneumonic that helps us memorize those six major classes of enzymes is just over the pill, where each of these letters represents the first letter of one of the major classes of enzymes. And so in this video we're going to focus on our first major class of enzyme, which is the oh, and our pneumonic, which stands for Occid Oh, reductase is, and so Occid a reductase is our enzymes that pretty much do exactly what they sound like. They dio and that is they catalyzed oxidation reduction reactions or redox reactions for short. And they do that by transferring electrons between molecules during a reaction. And so recall from your previous chemistry courses that substances that lose electrons during a reaction are oxidized, whereas substances that gain electrons during a reaction are reduced because they're gaining negatively charged electrons, and so their overall charge is being reduced. And so notice down below. In our example, we have a little pneumonic to help you guys memorize oxidation reduction reactions and that no, Monica's just Leo the Lion goes Ger, which I'm sure you guys have probably heard before and your previous chemistry courses. And so the Leo here just stands for lose. Electrons is oxidation, whereas the ger here stands for gain, electrons is reduction. And so down below, we have a little image of a lion that has a name tag that says Hello. My name is Leo, and he's shouting ger. And so hopefully by memorizing Leo, the lion goes ger. Then you guys will be able to understand all of your oxidation reduction reactions. Now it's also important to note that electrons can actually typically be transferred via hydrogen and or oxygen atoms. And so whenever you see that hydrogen or oxygen atoms are being transferred between different molecules in a reaction, that's a good indication that that could be an oxidation reduction reaction. And so what I also want you guys to note is that a classic example of an oxygen reductase is the enzyme lactate di hydrogen is or L. D. H, which is an enzyme that is incredibly important for anaerobic respiration, and we'll be able to talk a lot more about this enzyme much later in our course. But for now, again, I just want you guys to know that lactate the hydrogen ease, or ldh, is an example of a knocks it over duck taste and so down below. What we have is the chemical reaction that lactate di hydrogen is catalyze is, and it catalyze is the conversion of l lactate and N A D plus into Piru bit n a. D H and an asset and so up above. We have a question that's asking which molecule is oxidized and which molecule is reduced well, thankfully, we have our pneumonic here, Leo the lion goes gerb and taking a closer look at this reaction, noticed that the n a d plus here as it goes from left to right, it becomes an n a D H. And the positive charge is missing, which means that its overall charge has been reduced and must have gained electrons in the process of being reduced. And so essentially, what we can say is from the left here to the right and a d H must have been reduced and it must have gained electrons, and a D plus must have gained electrons. And of course, if it's gaining electrons, that must. That means that it must have gained the electrons from the Onley. Other substrate here l lactate, Which means that l lactate must have been oxidized or it must have lost electrons. And so, essentially, what we can say is that l act as it goes from left to right and breaks up into pie roof and this high, uh, acid right here. It must have been oxidized. And so we can say that the L lactate here is the molecule that is oxidized and the n a d plus here is the molecule that is reduced in this reaction from left to right. And so, essentially, there are some clues in here that can help us determine that this is an oxidation reduction reaction. One of the clues is that the n a D plus here is gaining a hydrogen over here. And we said previously that hydrogen transfers between molecules is a sign that electrons are being transferred and that it's a sign that it is an oxidation reduction reaction. And so because any d plus is gaining this hydrogen here, it's actually gaining the hot the electrons that are associated with that hydrogen because there is a hydride shift that's present, which might sound familiar to you guys from your previous organic chemistry courses. But if not, that's OK. Essentially, what we're saying is that hydrogen atoms can be associated with electrons. And when this extra hydrogen here that's in the back of a lactate, essentially it gets transferred over to the N A D plus, and the electrons that are holding it together are also transferred along with it. So the N A T plus not only gains the hydrogen, it also gains the electrons that were associated with that hydrogen. And that's why it's gaining the electrons and becoming reduced here. And so in the process, noticed that the L Lactate, on the other hand, is going to be losing this set of electrons. And because it's losing the electrons, it's getting oxidized. Now notice that the L lactate, if you compare its overall charge to the overall charge of the pyre of it, that they're exactly the same. And that's not what we would expect if a molecule is losing electrons, if it's losing negatively charged electrons, its overall charge should be getting more positive. But we don't really see that reflected when we compare the pyre of it to the l A tape, but we have to realize that the l lactate here is actually being broken up into not just piru bit. It's also being broken up into this acid over here. And really, the positive charge that we feel like should be on the pyre of it is being reflected by this acid here. And so another thing that you could have realized is that noticed that the pyre of it here actually has mawr bonds to the oxygen atom. And so over here there are only three bonds, two oxygen atoms. Whereas over here, in the pyre of its structure, there are four bonds and the more bonds that you have to the oxygen atom, the more likely you're going to be oxidized mawr, oxygen, mawr, oxidation. And so, essentially, this concludes our lesson on Oxydol Reductase is and will be able to get some practice in our next video. So I'll see you guys there

Which of the following is an indicator that a reaction is catalyzed by an oxidoreductase?

• A. Loss of a functional group.
• B. Loss of H₂O.
• C. Loss of a hydrogen.
• D. Loss of a substrate.

So now that we've covered our first major class of enzyme, the Oxydol reductase is we can move on to our second major class of enzyme, which in our demonic over the hill is the tea. And of course, the T stands for transfer races and transfer aces are enzymes that pretty much do exactly what they sound like they do, and that is, they catalyze the transfer of functional groups between molecules. And so it turns out there are actually many different types of trance races, and that's because there are many different types of functional groups. And so an example of a transfer race is an amino transfer race, which, of course, transfers amino groups between molecules. And so a very specific amino transferees is the enzyme allen in Trans Am anus, which is very important for the metabolism of a very specific amino acid. Alan, I mean. And so Alan, in Trans Am, unease converts El Al Inning into Piru bait, and in the process, what it does is it transfers. The amino group from El Al Inning over to Alfa Keto glued a rate, and it also transfers the Carbonnel Group on Alfa Keto, glittery over toe El al Ani, and in the process, it converts El Al Inning into Piru bait, and it converts Alfa Keto, glittery into l glutamate. And so moving forward, we're gonna talk about a lot of different types of trance phrases. But for now, all I want you guys to be able to do is recognize that an enzyme that catalyze is the transfer of functional groups is likely to be a transfer raise. And so we'll be able to get a little bit of practice and our next video, so I'll see you guys there.

Kinases add phosphate groups to molecules. Kinases are an example of which class of enzyme?

• A. Oxidoreductase.
• B. Phosphorylase.
• C. Hydrolyase.
• D. Transferase.

So now that we've covered the first two major classes of enzymes, oxidative reductase is and transfer races, we can move on to our third major class of enzyme, which in our pneumonic over the hill is the H. And of course, we know the H stands for hydro lionesses or just hydra laces. And so hide rely asses are enzymes that catalyze hydraulics, ISS reactions. And so recall from our previous lesson videos that hydraulics reactions are just reactions that break bonds by adding water. And we can see that in the prefix hydro, which means water. And so it turns out there are many different types of hydro lie aces, including Pep. Today's is lit paces and nucleus is which, respectively, hydrolyzed proteins, lipids and new click acids. And so recall from our previous lesson videos that trips in is an example of a pep today's and so down below. In our example, we can see that we have a poly peptide chain that extends on both sides, and we're treating our poly peptide chain with trips and and recall from our previous lesson videos that trips and does it split in after a night's ward, so it cleaves after amino acids that have a license or an Arjun Ing as the our group. And you can see here that this pink bond here is the peptide bond that's being cleaved. And it's on Lee cleaved in the presence of water. And so over here on the right with the products, you can see that the water is incorporated into the amino group with two hydrogen and the car Boxley group with one oxygen, and that cleaves the bond and generates poly peptide fragments. And so moving forward in our course, we're gonna talk about a lot of different types of hydro laces, and we'll be able to get some practice with these concepts here in our next practice video, so I'll see you guys there.

Below is a reaction in the oxidative phase of the pentose phosphate pathway catalyzed by the enzyme gluconolactonase. This enzyme would be classified as what type?

• A. Transferase.
• B. Hydrolyase.
• C. Lyase.
• D. Isomerase.

All right. So now that we've covered the first three major classes of enzymes, Oxydol Reductase is transfer races, and Hydro Lioce is we can move on to our fourth major class of enzyme, which in our pneumonic over the hill is the I. And of course, the I stands for Aissami races and I som races are enzymes that pretty much do exactly what they sound like, which is catalyzing the creation of an ice. Um er and of course, they do that by shifting functional groups around to different locations within the same exact molecule. And so recall from our previous lessons that ice swimmers are just molecules that have the same exact chemical formula with just a different arrangement of Adams. And so a classic example of a nice armories is the enzyme try owes phosphate ice armories, which produces a nice summer during like colossus. And later in our course when we covered like Hollis is in more detail, will revisit this try owes phosphate ice armories enzyme Now down below. In our example, we're showing the the reaction that try owes phosphate I summaries. Catalyze is and it catalyze is the conversion of die hydroxy acetone, phosphate or D H a p into glycerol to hide three phosphate or G three peat. And essentially, what you'll notice is the only difference between D. H. A. P and G three p is the arrangement of the atoms because they have the same exact chemical formula and therefore they are ice summers of one another. And so die hydroxy acetone has three hydroxy group on the end, and it has a carbonnel group and the middle over here, whereas glycerol died. Three phosphate has the Carbonnel group on the end and the hydroxyl group in the middle ish and so again, because there is this creation of a nice summer that classifies, Try owes phosphate I summaries as an ice armories. And so again we'll be able to get a little bit of practice in our next practice video. So I'll see you guys there.

What class of enzyme is required to convert a cis-fatty acid into a trans-fatty acid?

• A. Oxidoreductase.
• B. Isomerase.
• C. Hydrolyase.
• D. Lyase.

All right, So now we're moving on to our fifth major class of enzyme, which in our pneumonic over the hill is the first L, which, of course, stands for live faces and lie. Aces are enzymes that either form or break bonds, and they do that with out redox reactions or the addition of water. And so the way that lies is former break bonds is, via addition elimination reactions, which should sound familiar to you guys from your previous organic chemistry courses. And so one thing to note that will help you recognize reactions that air catalyzed by Lioce is is to know that lioce is typically either create or remove double bonds or rings in the process. And so a classic example of Elias is the enzyme Piru vit d car box Elise, which catalyze is the conversion of pyro of it into a CDO alga hide and carbon dioxide. And so one thing to note here is that there is a bond being broken. So this bond right here is being broken, and in the process, this molecule right here, this portion of the molecule is being released as a carbon dioxide molecule. And what I want you guys to notice is on the left hand side of our equation. Over here, there are a total of two double bonds, but on the right hand side of our equation, notice that there are a total of three double bonds, which means that a double bond has been created in the process. And that is a good hint that this reaction is catalyzed by a lioce. Now, another thing that I want you guys to notice is that the reaction here is balanced. So if we count the total number and types of Adams on the left hand side of the equation, it will equal the total number and types of Adams on the right hand side of the equation. And so we know that water is not being added. Toe break this bond right here because if water were being added, then we would expect there to be an additional oxygen atom. But on the left, we have a total of three oxygen atoms, and on the right, we still have a total of three oxygen atoms. So no water molecule was added to break this bomb. And another thing that you'll notice is that, um really. We're adding this hydrogen into this molecule over here, And then again, we're releasing this part of the molecule as a CEO to So there's no transfer of electrons from one molecule to another molecule. So this is not an oxidation reduction reaction. And so, of course, thes air. The signs of, uh, knowing that Peru, Dhi Qar, Boxley is a lice, and we'll be able to apply the concepts that we've learned here moving forward. So I'll see you guys in our next video.

Which of the following best describes the function of a lyase enzyme?

• A. To facilitate a reaction where two substrates form one product without the use of water.
• B. To facilitate a reaction where one substrate forms two products with the use of water.
• C. To cleave bonds via the transfer of electrons between molecules.
• D. To tell fibs.

and this video, we're going to talk about our sixth and final major class of enzyme, which in our pneumonic over the hill is the second l, which, of course, stands for like cases and like cases are enzymes that use energy such as a t. P in order to catalyze the legation or the CO Vaillant joining of two separate molecules together as one single molecule. And so a classic example of a lie gates is DNA lie gates, which is critical for DNA replication. Ah, process that will talk a lot more about later. In our course now down below. In our example, image noticed that we have to separate DNA molecules. We've got this DNA molecule over here on the left and this DNA molecule over here on the right and also notice that DNA like case is able to use energy such as a t. P. In order to catalyze the reaction between these appropriate functional groups on these different DNA molecules in order to co violently join these separate molecules together as one single molecule. And so in our next practice video, we'll be able to get some practice utilizing these concepts. Now, some of you may have realized that magnesium is also being utilized by DNA like gays. And that's because magnesium is a co factor for DNA like gays and that transitions us into our next lesson video, where we'll talk about co factors, so looking forward to seeing you guys there.

alright. In this video, we're going to do a quick recap on the six major classes of enzymes and the pneumonic that helps us memorize those six major classes is just over the hill, where each of these letters represents the first letter of one of the major classes of enzymes. And so the O is for Oxydol. Reductase is the tea is for trance races. The H is for hydro Elias is the I I som races. The first l is for lice is and the second l is for like cases. And so remember the enzymes literally help reactions get over the hill because they all decrease the energy of activation. Now, for the first class of enzymes, the Oxydol reductase is they do pretty much exactly what they sound like, which is catalyzed oxidation reduction reactions or redox reactions. And they do that by the transfer of electrons between molecules and so over here on the right, left, which will notice is we have molecule a here which has two pairs of electrons, these two blue balls and it's transferring them over to molecule B. And so molecule B ends up with the two electrons and molecule a is lacking electrons, and so Ricard pneumonic to help us memorize oxidation reduction reactions is just Leo the lion goes Ger, where Leo stands for lose electrons, oxidation and ger stands for gain electrons reduction. And so because molecule A here is losing electrons as it goes from this side over to this side Here we can say that molecule A is being oxidized. And then molecule B, on the other hand, which is going from here over to here, is gaining two pairs of electrons. And so for that reason, it's being reduced so well, right reduced over here. All right, so moving on to our second class of enzymes, we have the transfer races, which also do pretty much exactly what they sound like. They transfer things between molecules, and the things that they transfer are functional groups, and so you can see that molecule A Here is transferring its orange functional group here over two molecule B, and so molecule B ends up with the functional group. So moving on to our third class, we have hydro. Elias is and recalled that the root hydro means water, and so Hydro Elias is break bonds by adding water to the bond. And so notice here that we have a bond here between substance A and B, a Covalin bond, and through the addition of water hydro laces are ableto cleave that bond and noticed that water is being added across his bond. And now molecule A is separate from molecule beak. So moving on to Aissami races, they also do pretty much exactly what they sound like, which is they create ice Immers and the way that they create I summers is by just rearranging atoms within the same molecule. And so notice that the functional group here on substance A This hydroxyl group is on the right side of molecule A. But after the reaction notice that the hydroxyl group is now on the left side of molecule A. So all that's happened is a rearrangement of the atoms and a creation of the ice. Um er and those are the types of reactions that I som races catalyzed now moving on to our first l Here we have lie aces and laces either break or form bonds, but they do so without redox reactions or water. And so here, from left to right, you can see that there's a Covalin bond holding together A and B together and, um, licenses are able to catalyze the cleavage of this bond here to separate A from B. But licenses are also able to catalyze the reverse reaction, and we'll see that in some of our examples moving forward in our course as well. And so that's why we're saying that laces are also able to form bonds now. Good indications of lies is are the change in the number of double bonds that air present from the reactant to the product side and the formation or the loss of a ring? And so those air signs that lie asses could potentially be present. And so moving on to our next on final major class of enzymes, we have the like cases which use energy in order to co violently join molecules together. And so here we can see that a T P is being utilized by the likes to co violently joined molecule A and B together, and you can see that a new Covalin bond has been formed, holding them together and so moving forward in our course, we're going to see examples of enzymes that fall into all six of these classes, So it's important to familiarize yourself with the types of reactions that they catalyze. So that concludes this recap, and I'll see you guys in our next video.

The presence of an electron acceptor such as NAD ⁺ indicates which class of enzyme?

• A. Oxidoreductase.
• B. Isomerase.
• C. Hydrolyase.
• D. Transferase.

Digestive enzymes are all examples of which class of enzyme?

• A. Ligase.
• B. Lyase.
• C. Hydrolyase.
• D. Transferase.

The reaction below is catalyzed by the enzyme arginase. What is the classification of this enzyme?

a) Hydrolyase. 

b) Oxidoreductase. 

c) Lyase. 

d) Ligase.

• A. Hydrolyase.
• B. Oxidoreductase.
• C. Lyase.
• D. Ligase.

Which class of enzyme catalyzes a reaction where the chemical formula does not change?

• A. Isomerase.
• B. Oxidoreductase.
• C. Transferase.
• D. Ligase.

What class of enzyme is required to combine two molecules using ATP?

• A. Lyase.
• B. Transferase.
• C. Oxidoreductase.
• D. Ligase.