All right, this is Joseph Kazeri with Mississippi College and this week in your bio11 lab, we are going to be working with enzymes. Now, something that enzymes do, enzymes are going to allow reactions to occur. Now in a chemical reaction if you've seen in chemistry or you should have seen in other sciences you have something like A and B arrow which means yield means something's happening chemical reaction is occurring to form C. Whereas we have your these items over here A and B are referred to as reactants because they're going to react together to form the product. Now that doesn't occur all by itself. Your body is going to be any organism, any biological system. We need to build things up. We need to put smaller things together to make larger things. So in order to do this, we need enzymes. So I am going to abbreviate that with the enzy because an enzyme is a catalyst. If you want to look up catalyst, it is a substance that takes place in a helps out in a chemical reaction but does not get used up in the reaction. This enzyme is not part of C. It just help A helps A and B come together. Now, where does this fit in to um in what we were discussing last week with those basic bio uh biological molecules? Well, an enzyme is a protein. Not all catalysts are proteins. Not all proteins are catalyst. Some proteins are used to are used as your tissues, your structure, holding cells together, right? Cytokeleton of the of the cell. others are going to help put things together. Those macroolelecules that we discussed last week, what do you think put together the glucose and fructose, all those uh all those monossaccharides to form one larger structure? What do you think put together those nucleic acids? Excuse me. Those nucleotides, uricil, all right. Um, edanine, guanine, all those others to form a larger nucleic acid. What put together amino acids? Because they were singular by themselves. But when you start binding them together, you get these peptides that go on and on and on. So even making proteins, they're made by other proteins. Typically, we just call them enzymes. They are the doers inside your cell. And this should make sense in chemistry. If you ever tried to synthesize something that is make something or you took two reactants you put it together to form one product you would use heat you may use palladium platinum something in there to help speed up the reaction. Usually you heat it up and it causes the reaction to occur right the heat helps speeds it up. In this case the enzyme allows this to occur at lower temperatures. But in chemistry you probably used heat to help break something down. That's the common thing. When you have something like, let's say, a sugar, you heat it up, you break it down to simple components such as carbon and usually moisture. So, we got reactants, we have products, but inside a biological system, enzymes don't act on reactants. Well, let's use another word. All right, get used to the word substrate or substrates. Substrates can form together to form a single product. But the opposite can be true because a single substrate an enzyme can act on it to form multiple products. These enzymes usually go by different names. We have uh um sucrace a lot of different types. We have lipase. We got amma. See, galactase, maltase. Oh, you know what? Sorry. Not galactise. It's just lactice. But when you look at all of these, you should notice that all of them end with the suffix ace. So whenever whenever you're doing reading, you see something that ends with ace, you should know that this is going to be an enzyme. It's acting on something. Sucrace acts on sucrose. And from last week, you should know that sucrossse is a disaccharide. Right? Lipase act on lipids. Emma is going to act on amalos. Maltase moltose. And lactase is going to act on another disaccharide lactose. So let's put this into a another little diagram. So here is a here are two substrates square part portion of it triangular portion we have substrate A and we have substrate B just like up here. Now they don't know it yet but A and B were made for each other. They might see each other around. They might bump into each other, but it'd be really nice if A and B had a friend in common that would that could help bring them together. Well, that's where we'll introduce the enzyme abbreviate E and Z. We're going to call her Natalie. Everyone knows a Natalie. You have two friends. They know them. They have something in common with them. As we see here, this enzyme protein, this enzyme has a very specific shape. Has something in common with both of them. It can actually help bring them together. That shape is very specific, right? Specificity is a term you need to be familiar with. It means that enzyme will only act with certain substrates. Here's another one. Let's throw another let's say uh here's substrate D. A weird shape. It's like upside down dorsal fin. Now D and B might be made for each other. But as if you might notice by looking at this location here, this enzyme having a little square structure part and uh substrate D having a little dorsal fin like sites for it to bind. This is called a this is their binding sites. Binding sites, binding sites or active sites. It ain't going to work with any just any substrates in this case. It's only going to work with A and B. So, this enzyme named Natalie say, "You know what? Hey guys, let's go together. Two cups and she brings them together." No, she shows up. She's there. She's a third wheel for a little bit and she sees that they're all together. It's forming a nice friendship complex is what we call this. When a bunch of molecules work together or attached to each other, we refer to it as a complex. But once Natalie sees our once she sees that A and B are both hitting it off, right, they're now a little squeezing, a little uh nudging them. When she sees that they're a happy couple, she's not going to hang around. This isn't her reaction. It's not her relationship. Well, she's going to be released and she's going to go off and do the exact same thing again with another couple that she knows. That's how enzymes work. and we don't need a lot of enzymes because this one is not used up. Now, the opposite can occur. In this case, we have a happy couple. This happy couple, they're fine. And let's go the other direction. There's other enzymes. Some enzymes build up. Some enzymes are going to work the other way and break down. In this case, we have a happy couple and there's an enzyme. We'll call her Sarah. Sarah's going to come be a third wheel and she's going to get in between this happy couple saying, "Hey, he doesn't treat you right. You know, I don't like his attitude. He should do something else for you. I don't know." So, it's putting a little tension there, adding those lines in there, right? And eventually, this Sarah She forms a complex with them. She's going to split up that happy couple into two products. And when she's done, what's she going to do? Right. Well, she's just going to go off and go do it again because that's how she gets her kicks. But the big thing here is is that these we have to see how things are put together by enzymes and they're broken down by enzymes. In lab, you're mostly going to be working in that direction. You're going to have these enzymes breaking things down. Now, a few things can change or can affect these reactions. If we change a few conditions, if you have different conditions that will affect your protein, your enzyme. So, let's think about a few of these. This happy couple A and B, what would allow this enzyme to help that reaction occur? What would help this happy couple come together? One thing would be if we had Well, first of all, we allow more time, we should be able to have more products. That's one thing. Another thing is what happens if we had more people like Natalie? More people like Natalie would help bring couples together forming more products. So we'll say concentration. we're going to see today or in this lab from this week for this week is that concentration it does not have to be very high. another item pH right now different uh these enzymes these proteins they react under very specific conditions and we said it's spec specificity means it has a very specific shape for a very specific substrates active sites so this shape that we see here it doesn't really have this nice geometric shape in reality it's some weird globular shape like we discussed in the last uh meeting the last video. Now this globular shape is very specific and if you change the shape that means it's from here and now it's going to look like maybe something not as bad, right? It might straighten out a little more goes to a simple structure from not as a globular complex structure. What we just did here is we denatured it. We denatured this protein. We changed the shape, excuse me, the structure. So therefore, we didn't change the function. We destroyed the function because now Sarah cannot do her job in that direction or Natalie cannot do her job in that direction. So what pH does every line we see here is a lot of amino acids. And what's happening with a change in pH change in pH it's going to cause these little hydrogen bonds between the amino acids to separate into these simple little more linear we'll say chains or structures. we just denatured it. Very similar type of denaturing is we see with high temperatures. A good example about this is cooking an egg. You have your egg yolk and you have that egg whites. Even though it's in green, the egg white that we see here is almost pure protein and it's clear. However, after you increase the temperature, right, we denature it. So all those little proteins that look like a glob, they're going to be changing their structure into similar shapes. So now that protein which was clear is uh structure is different and it looks different to us too. Should be a cloudy white. They were denatured. And two other things, there's some random chemicals out there. We can go with some poisons, cyanide, heavy metals, um cadmium, uh lead, uh some soaps. They can also change the shape of proteins, right? denature them to another simpler structure. Radiation as is from the sun also does the same thing separate changing that shape denaturing it to a shape such as this. These bottom four structures are these are factors that influence structure. These are denaturing agents. All right. So, a few little reminders. This week you're going to be working with uh substances. You're going to be working with acids and bases. So, please wear your goggles. Do wear your goggles and be careful. We're dealing with hot water. Once again, hot water baths. Uh if there any glasses broken, tell the instructor and dispose of it. Get some new ones. And once again, we'll be working with several substances. We do not want to cross or excuse me, crosscontaminate. Also, solids go in the garbage. Only fluids, substance, the liquids can go down the sink. So, if something dumps out in of your test tube into the sink, get a napkin or paper towel and please pick it up. Also, start on procedures two through five. It's because those have incubation times. They're you're going to have to get a timer, watch the clock, something, get those started, and then when they are incubating, go back to your first procedure. All right, with that this is Josei signing out ofology 111 experiment two.