Enzyme kinetics plotting a slope replot

[skyblu280]

hi,

My instructor has given us an assignment where we have to diagnose the type of enzyme inhibition it is. I diagnosed it as a competitive inhibitor and am trying to do a slope replot to find my value for KI.

For the slope replot, you just find the slope of the each line? is it the same as having excel find the linear regression line and taking that slope to make a slope replot? Because that's why I did but my graph is turning kind of hyperbolic

 

[epenguin]

hi,

My instructor has given us an assignment where we have to diagnose the type of enzyme inhibition it is. I diagnosed it as a competitive inhibitor and am trying to do a slope replot to find my value for KI.

For the slope replot, you just find the slope of the each line? is it the same as having excel find the linear regression line and taking that slope to make a slope replot? Because that's why I did but my graph is turning kind of hyperbolic

We are of course incredibly brilliant but even we have some limitations.

E.g. we are fairly telepathic but not totally. E.g. to be on the safe side it would be better to tell us just what you are plotting and replotting.

We might also get ideas better if you posted pics of your plots.

Another of our defects is some of us are touchy, ratty or peevish. If we answer one of your questions and hear no response ever we might wonder whether to try and help out the next time. :tongue2:

 

[skyblu280]

Hi,

Sorry for not thanking you earlier lol. But I think got the slope replot thing down.

 

[epenguin]

Hi,

Sorry for not thanking you earlier lol. But I think got the slope replot thing down.

It's not about thanks, it's about thinking through an answer in a dialogue and then being left in the air. Like if you gave your results, plots and conclusions to your Prof. and then never head a thing.

Anyway glad you have sorted it.

Maybe this was the thing called the Dixon plot.

 

[DeeNos]

Hello, it sounds like you are on the right track with your diagnosis of competitive inhibition and using a slope replot to determine the KI value. To answer your question, yes, the slope of each line on the slope replot would be the same as the slope of the linear regression line calculated by Excel. However, it is important to note that the slope replot is typically used for non-linear data, so if your graph is turning out to be hyperbolic, it may be due to the nature of your data and not necessarily an error in your calculations. It may be helpful to consult with your instructor or a peer to confirm your results and ensure that your methodology is correct. Additionally, double-checking your calculations and making sure your data is accurate may also help to clarify any discrepancies in your results. Good luck with your assignment!