Talk:Competitive inhibition
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When the article describes a detail about classical competitive inhibition in "the substrate's apparent affinity for the site is decreased," I disagree with the statement. I believe the apparent substrate affinity is actually increased and not decreased. In competitive inhibition, addition of more substrate will out compete the inhibitor and overcome the inhibition of the enzyme's catalytic rate; thus, the Vmax will be the same and only Km will be altered. For the true competitive inhibitor, the Vmax' (apparent Vmax for inhibited enzyme) will be the same as the real Vmax, while the Km' (apparent Km for the inhibited enzyme) will be greater than the real Km. Note that Km (Michaelis constant) represents (for enzyme reactions exhibiting simple Michaelis-Menten kinetics) the dissociation constant (affinity for substrate) of the enzyme-substrate (ES) complex.
I agree, this entry needs fixing. It is incorrect to say that maximum velocity will not be attained in competitive inhibition.
The affinity is the reciprocal dissociation constant.
Allosteric inhibition is something completely different than competitive inhibition, isn it? I thing that this article requires major revision... —Preceding unsigned comment added by MR Deidra (talk • contribs) 12:05, 3 September 2007 (UTC)
- I was thinking the same thing. I'm removing the text about there being two types of competitive inhibition. If I'm mistaken here please re-insert this with more information that resolves more clearly the difference between "non-classical" competitive inhibition (I've not heard of this) and non-competitive/uncompetitive inhibition, and how this "non-classical" competitive inhibition is "competitive" even though it binds at an allosteric site.--Xris0 18:17, 12 September 2007 (UTC)
Getting V vx. [S] and Lineweaver-Burke plots up here would probably be useful if anyone has the time. --Xris0 18:23, 12 September 2007 (UTC)
With respect to the affinity of the substrate, I think what the second comments are trying to say is that Km is similar to the dissociation constant, and therefore an increased Km is indicative of weaker affinity for the enzyme, so the correct statement would be to say that the "apparent affinity of the substrate for the enzyme is decreased". I agree plots (and nicer equation style) would be nice, but I don't know how to add one.A2a2a2 01:58, 15 September 2007 (UTC)
Under the "mechanism" heading it first says "In competitive inhibition, the inhibitor binds to the same active site as the normal enzyme substrate" then a few lines down it says "Note that the inhibitor does not necessarily have to bind to the same active site that the substrate would bind to"
so which is correct? don't ask me, it just seems to contradict itself.124.178.136.93 (talk) 03:29, 24 April 2008 (UTC)
[edit] Do competitive inhibitors connect forever?
Curiously speaking: Does the competitive inhibitor stay on the active site "forever"? Or does it disconnect so that at some point a substrate can connect on to it? That's the only way I can understand that Vmax isn't lowered. An increase in substrate concentration shouldn't increase the rate if there's no more active sites available. The X (talk) 11:10, 9 May 2008 (UTC)
