Electrostatic and Metal Ion Catalysis - Video Tutorials & Practice Problems
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concept
Electrostatic and Metal Ion Catalysis
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So at this point, we know that there are four main types of enzyme catalysis, and we already covered the very first one, which is general acid based catalysis. And so in this video, we're gonna move on to our second main type, which is electrostatic ca Tallis, ISS. And so, in our last lesson video, we said that the charges on a molecule can destabilize that molecule. And so, through electrostatic Catala, sis enzymes are able to directly stabilize charges in the transition state. And they do that by forming electro static non co violent interactions with the transition state. And so enzymes can take very specific amino acids and position them perfectly in the active site so that those amino acids can directly form electrostatic bonds with the transition state and that stabilizes the transition state and allows the entire reaction to occur faster and so down below. In our example of electrostatic catalysis, this big red thing right over here is our enzyme. And of course, our enzyme has very specific amino acids positioned in the active site. So notice that we have an Asper Tate amino acid here. Listen, over here, Argentine at this position and glutamate over here. And these are some of our charged amino acids. And so these specific amino acids are positioned such in such a way that they're able to form electrostatic interactions with the transition state. And our transition state is this distorted molecule here, which is unstable. And, of course, stabilizing The transition state will allow the entire reaction to occur faster. And so that concludes. Our lesson on electrostatic Potala, sis, and the main take away here is that enzymes are able to directly form these electrostatic interactions with the transition state. And so, in our next lesson video, we'll talk about metal ion ca Talese's so I'll see you guys in that video.
2
concept
Electrostatic and Metal Ion Catalysis
Video duration:
2m
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All right. So now we're moving on to our third main type of enzyme catalysis, which is metal ion catalysis and with metal ion catalysis. The enzyme indirectly forms electrostatic bonds with the transition state via its metal ion co factors. And so metal ion catalysis is really just a type of electrostatic catalysis where the interactions formed between the metal ion co. Factors and the substrates. And this can of course, orient substrates in the appropriate way and or stabilize the transition state, which will both allow the entire reaction to proceed at a faster rate and so down below. In our example, we're going to take a look at the Dhi Qar box elation of a substrate via metal ion catalysis. And our substrate is this molecule that's down below and notice that our enzyme, which is the red structure, is utilizing a copper metal ion co factor, and the amino acids in the active site of the enzyme are not directly interacting with the substrate. Instead, they interact with the copper metal ion co factor, and the copper metal ion co. Factor is the one that directly interacts with the substrate. And so you can see in this example here, This copper Adam is stabilizing these negative charges in the oxygen atoms, and so you can see the reaction mechanisms for this reaction. And essentially, what's happening is this portion of the molecule here is being removed as a CEO to molecule. And that generates this immolate molecule here, which is just the carbon carbon double bond with an oxygen branching off. And notice that the copper metal ion co. Factor is still continuously forming these electrostatic interactions with the substrate to stabilize again. These negative charges in the oxygen atoms and that allows the reaction to proceed at a faster rate. And so you can see the rest of the reaction mechanism here allows for the pro nation of this double bond here, and that generates this key tone, which is just a carbonnel group, with two are groups branching off. And so essentially the main take away of this video is that metal ion catalysis differs from electrostatic catalysis and that electrostatic catalysis enzymes directly interact with substrate. But with metal ion catalysis on the other hand, enzymes indirectly interact with substrate via the metal ion co factor. And so that concludes. Our lesson on metal ion catalysis. And in our next lesson video, we'll move on to our fourth main type of enzyme catalysis, which is CO Vaillant catalysis. So I'll see you guys there.
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Problem
Problem
Catalysis by the enzyme urease is inhibited in the presence of Hg, Cd, or Co ions. What could this information potentially suggest about the catalytic mechanism of urease?
A
Urease uses acid-base catalysis.
B
Urease uses covalent catalysis.
C
Urease uses noncovalent catalysis.
D
Urease uses metal ion catalysis.
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Problem
Problem
Which of the following best applies to metal ion catalysis?
A
A covalent bond forms between enzyme and substrate.
B
Catalyst may participate in oxidation-reduction reactions by changes in the oxidation state.
C
May use amino acids such as aspartate or lysine for protonation or proton abstraction.
