Optimal Enzyme Conditions - Video Tutorials & Practice Problems

Optimal Enzyme Conditions

in this video, we're gonna talk about optimal enzyme conditions. So it turns out that proper enzyme catalysis requires a very specific set of conditions, including a very specific pH and a very specific temperature. And so moving forward, we're first going to focus on optimal pH. And then later in our next video, we'll focus on the optimal temperature. And so we know that most enzymes have an optimal pH that allows them to display their greatest amount of activity. Now, we also know that most enzymes are proteins, and so enzymes and proteins are both sensitive to pH. And different enzymes are gonna have their own optimal pH. Now why is it that enzymes air sensitive to the pH well recall from our previous lesson videos that the charges of ionized ball amino acids actually varies with P H and so pH changes could cause active site amino acids or amino acids in the active site to change their charges? And the charges of amino acids in the active site could potentially be super important for enzyme catalysis. And so if we change those charges, then we could potentially hinder enzyme catalysis. Now, later, in our course, we're going to talk a lot more details about enzyme catalysis when we talk about different types of enzyme catalysis. But for now, all I want you guys to know is that the charges of amino acids are not only potentially important for enzyme catalysis, but they're also important for maintaining protein structure, specifically the tertiary and Quaternary structure. And so, by changing the pH significantly enough, that could cause the enzyme to de nature. And, of course, if we d nature the entire enzyme, then hens I'm Catala sis will definitely be hindered. And so, in our example below, it's asking us what is the approximate optimal pH for Pepsi and for chemo trips in and soap. Epson's curve is in the black and kinda traipses curve is in the pink here, And so starting with Peps and its optimal pH is gonna be where it displays the greatest amount of activity. So we have enzyme activity on the Y axis and the pH on the excesses. So what do you guys think? What is the optimal pH for Pepsi in? That's right. So if we take the optimal pH, it's gonna be right where it displays its optimal activity so it's gonna correspond with the X axis where it has the highest peak here. And so that looks like a bit about 1.5 or so. So pep sins optimal. PH is about 1.5 now, if we do the same for chemo trips, and it's gonna be right where it displays its highest amount of activity, and so that's going to correspond with the X X is right just above eight. So it's about eight, and so that is the optimal pH of Pepsi and the optimal pH of chemo trips. And that's a good thing, because Pepsi is typically found in the stomach, where the pH is super super acidic, like about two or so soap. Epson is going to be very active in the stomach and kinda trips and has found more so in the small intestine, where the pH is a little bit higher, and this allows it to operate better in those higher PHS. And so this concludes our lesson on optimal pH. And in our next lesson video, we'll talk about optimal temperatures, so I'll see you guys there

Optimal Enzyme Conditions

So, in addition to having optimal pH. Enzymes also have an optimal temperature where they can work at their best and display their greatest amount of activity. So if we take a look at this graph down below, where we have the enzyme activity on the Y axis and the temperature in degrees Celsius on the X axis, notice that we have these two different curves. We have this green curve here that represents the human enzymes, and then we have this red curve over here that represents the thermo Filic bacterial enzymes. And so taking a look at this green curve first notice that the greatest amount of enzyme activity is showing up right around a temperature of degrees Celsius. And so it's actually no coincidence that human enzymes have evolved to have an optimal temperature right around 37 degrees Celsius. And that's because the human body temperatures maintained right around 37 degrees Celsius. Now, if we take a look at this thermo filic bacterial enzyme perv over here, notice that this time the greatest amount of enzyme activity is showing up at a temperature that's much, much hotter, right around 77 degrees Celsius. And so again, it's no coincidence that the thermal Filic bacterial enzymes have evolved toe have an optimal temperature that's so hot right around 77 degrees Celsius. And that's because thermo filic bacteria live in very hot environments, such as the hot springs that you confined in Yellowstone National Park and also the hot hydrothermal vents that could be found on the deep sea ocean floors. And so imagine a scenario where we replace all of the thermo Filic bacterial enzymes with human enzymes. But the thermal filic bacteria are still living in their hot environments. In that scenario, all of the human enzymes would de nature in those hot environments and the thermo Filic bacteria would die. And so you can see how the, uh, enzymes have evolved to have optimal conditions that reflect the living conditions that they face on a daily basis. And so we'll be able to apply these concepts that we've learned about optimal enzyme conditions throughout our course and in our practice problems. So I'll see you guys in our next video

The best way to increase the reaction rate for an enzyme saturated with substrate is always to:

• A. Increase the pH.
• B. Increase the temperature.
• C. Increase [enzyme].
• D. Increase [substrate].

Which of the following statements about enzymes is false?

• A. Enzymes carry out multiple rounds of a given chemical reaction.
• B. Enzymes accelerate the speed at which reactions get to equilibrium by lowering the activation energy barrier.
• C. Enzymes can denature under highly acidic or basic conditions.
• D. Enzymes push the reaction equilibrium toward product formation.
• E. Enzymes are biological molecular catalysts.