Lineweaver-Burk Plot Explained
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- Опубліковано 5 лют 2025
- Today we will look at the Lineweaver-Burk plot, which is central in enzyme kintetics. A typical curve of enzyme kinetics plots the velocity or rate of reaction on the y-axis and the substrate concentration on the x-axis. The rate of reaction increases with the substrate concentration but the growth is logarithmic, meaning that it starts plateauing like this. The maximum velocity of the reaction or Vmax is therefore only theoretical since the reaction never truly plateaus in this manner. Therefore we get an error in both our Vmax as well as Km.
To solve this, we can use a Lineweaver-Burk plot, but do not worry about this quite yet. First, recall the Michaelis-Menten equation v = Vmax times [S] divided by Km + [S] where v is the rate of reaction, Vmax is the theoretical maximum possible rate of the reaction, S is the concentration of substrate and Km is the Michaelis constant. If this equation is inversed we get 1 over V = Km + [S] over Vmax times [S]. This can be modified so that we instead get 1 over V = Km over Vmax times [S] + 1 over Vmax.
Now let’s compare this new equation to the general equation of a straight line: Y = mx + c, where m is the gradient or steepness of the line and c is the y-intercept. We can match the components of the new equation to those of the general equation of a straight line. In other words, 1 over V will be the Y part, Km over Vmax will be the m part, 1 over [S] will be the x part and 1 over Vmax will be the c part.
Let’s take another look at the Lineweaver-Burk plot with that in mind. Take a quick moment and pause the video to see if you can fill in these components in the proper places. Ok here we go:
1 over V is the y-axis
Km over Vmax is the gradient of the slope
1 over [S] is the x-axis, 1 over Vmax is the y-intercept
-1 over Km is the x-intercept and
Due to it being a straight line graph the estimate of Vmax becomes easy since we can just look at where the y-intercept occurs to get the value for 1/Vmax. Furthermore any change in the value of Vmax or Km can easily be spotted from the graph. As a result this graph is one of the most useful ones for understanding enzyme inhibition.
If you want to understand the Lineweaver-Burk plot as it relates to Enzyme inhibition, check out this video! UNTIL NEXT TIME!
![Lineweaver-Burk plot (Enzyme Kinetics) - Vmax, Km & [S] - Biochemistry 🧪](http://i.ytimg.com/vi/nivkBZkmu14/mqdefault.jpg)
I really appreciate these videos, your explanations are concise and elegant. I know they may not be getting as many views as you might like, but just know you added value to my life, so thank you!
Thank you so much for those kind words!🙏
On the contrary, I'm actually very happy with how many views I get!🥳
Had a quiz in my biochemistry class over this last week because I did not understand ANYTHING that was going on. Watched this video the morning of, got the hang of it, and got an A!!! THANK YOU SO MUCH
That’s amazing! Great job and thank you for telling me.
Instantly made my day better!🙏❤️
Wonderfully explained, thank you so much!
Thank you for your kind words! Appreciate it👍
Hey Lucas, any chance you could make a vid on first and second order kinetics? Your format is super friendly and easy to learn with compared to other creators.
Hi! I'll add it to my todo list but for right now I'm doing almost all of my videos on Google Sheets as it relates better to my day job.
You should have sticked to making these types of videos in biochem, I assure you that there is a need for well explained concepts in biochem in the sea of videos that are not very good.
Hi, thank you. I might return to it in the future but for now, videos on Google Sheets match better with my regular job.
So helpful, thanks!
Happy I could help!😇♥️
From what I'm gathering... If you're asked to find Km or Vmax, should you use the x-int and y-int to solve for them? I keep wanting to use the method of [S]=Km at 1/2(Vmax). Is it wrong to look at a MM plot and say what Km is equal to by using that method?
How did do u get - 1/km
If you compare that michealis equation to the equation of a straight line,get the x intercept by equating y axis to zero.solving that will give you x intercept as -1/km
Bhai ooncha bola kro