How Does an Inhibitor Affect Enzyme Kinetics?

  • Thread starter Thread starter leopard
  • Start date Start date
Click For Summary
The discussion focuses on calculating Vmax and KM in the presence and absence of an inhibitor, with a specific emphasis on determining the type of inhibitor. The user calculated KM as 25E-6 M, questioning a discrepancy with their textbook, which suggests a range of 20-24 M. The response highlights that textbooks can contain errors, and the user's calculation may be accurate. The inhibitor type is identified as noncompetitive. Overall, the conversation emphasizes the importance of verifying calculations and understanding enzyme kinetics.
leopard
Messages
123
Reaction score
0
2pzy4xh.jpg


I'm asked to calculate Vmax and KM from this, with and without the inhibior, and answer what kind of inhibitor it is.

I have plotted 1/ vs 1/V0 here:

2ekrrz9.jpg


The x-intercept is -1/KM. The value I get is -1/KM=-4E4, so that KM=25E-6. Does this mean that KM=25E-6 M? My book says 20-24 M. Of course, I might have been unaccurate in drawing the graph, but why do I miss by a factor of 1E6?
 
Physics news on Phys.org
Maybe the book says (20-24)uM (micromolar)?

But at your level I have some news for you, part bad part good.

The bad news is sometimes books are wrong. Contain slips. Misprints. That the author does not pick up - can be quite hard to see when you read you own thing.

The good news is you are sometimes right. :smile:
 
Last edited:
Am I right this time?
 
Looks right to me.:approve: Of course I could be wrong.:biggrin:

What is your answer to the other part of the question, type of inhibitor?
 
Noncompetitive.
 
leopard said:
Noncompetitive.

Right
 

Similar threads

Graphing the Results from Kinetics Experiments with Enzyme Inhibitors
  • · Replies 1 ·
Replies
1
Views
4K
Enzyme Kinetics- is my summary correct?
  • · Replies 7 ·
Replies
7
Views
2K
Enzyme Kinetics: Measuring Inhibitory Effects and Determining Km and Vmax Values
  • · Replies 2 ·
Replies
2
Views
4K
How Does Penicillinase Affect Penicillin Kinetics in Staphylococcus Aureus?
  • · Replies 1 ·
Replies
1
Views
5K
Enzyme kinetics Km Vmax Alcoholdehydrogenase
  • · Replies 3 ·
Replies
3
Views
5K
Competitive inhibitors (biochemistry)
  • · Replies 4 ·
Replies
4
Views
9K
Do Different Temperatures Affect Enzyme Activity in a Parabolic Arrhenius Plot?
  • · Replies 1 ·
Replies
1
Views
2K
Does climate change affect air density at altitude (scale height)?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Power spectral density of a laser's frequency noise
  • · Replies 6 ·
Replies
6
Views
2K
How Does Fossil Fuel Combustion Impact Atmospheric CO2 Concentration Annually?
  • · Replies 6 ·
Replies
6
Views
7K