Lineweaver-Burk Plot
A double reciprocal plot used to determine Vmax and Km of enzymes.
Practise Kinetics & Equilibrium All Kinetics & Equilibrium topics
A double reciprocal plot used to determine Vmax and Km of enzymes.
Practise Kinetics & Equilibrium All Kinetics & Equilibrium topics
The Lineweaver-Burk plot is a double reciprocal graph of 1/v against 1/[S], which transforms the Michaelis-Menten equation into a straight line. The intercept on the vertical axis is 1/Vmax, and the slope is Km/Vmax, so both kinetic constants can be read from the graph. The plot is useful for recognizing the type of enzyme inhibition, because different inhibitors change the slope and intercept in characteristic ways. However, the double reciprocal transformation exaggerates experimental errors at low substrate concentrations, so modern analysis usually fits the original data directly by nonlinear regression. Historically the plot was a major tool in enzyme research.
Key ideas: The line is 1/v = (Km/Vmax)(1/[S]) + 1/Vmax. The x intercept equals -1/Km and the y intercept 1/Vmax. Inhibitor patterns: competitive lines meet on the y axis, noncompetitive lines meet on the x axis, and uncompetitive inhibition gives parallel lines. Use points over a wide range of substrate, from about 0.2 Km to 5 Km.
Common mistakes and connections: Students read the x intercept as +1/Km and forget the minus sign, or take the reciprocal of intercepts incorrectly. Points at low [S] sit far from the origin and dominate the fit, which skews the lines, so weighting or nonlinear fitting is better. Alternatives are Eadie-Hofstee and Hanes plots. Interpretation ties directly to the study of enzyme inhibition.
Plotting 1/v against 1/[S] makes a line with intercept 1/Vmax and slope Km/Vmax, so both constants can be read from the graph. The interactive lesson shows this as a live animation or chart.
A competitive inhibitor increases the slope of the Lineweaver-Burk line but leaves the intercept on the 1/v axis unchanged.
A double reciprocal plot used to determine Vmax and Km of enzymes.
Lineweaver-Burk Plot is a advanced topic in Kinetics & Equilibrium. It builds on beginner and intermediate topics, so review those first if needed.
Study these earlier topics in Kinetics & Equilibrium first: Heterogeneous Catalysis, Enzyme Catalysis, Michaelis-Menten Kinetics.
The next topics in Kinetics & Equilibrium are Enzyme Inhibition and Autocatalysis.
Yes. The interactive lesson includes a self-check question on Lineweaver-Burk Plot, and the Kinetics & Equilibrium quiz draws on every topic in this area.
Lineweaver-Burk Plot is topic 36 of 91 in Kinetics & Equilibrium.