How to Calculate KCAT and VMAX


Enzymes increase the speed of reactions by catalyzing the substrate. An enzyme binds with a substrate, changing the substrate into a new product. Throughout an enzyme reaction, the enzyme remains unchanged. The Michaelis-Menten equation describes the rate of conversion at a given substrate concentration and can help calculate the amount of time required to convert a substrate. The equation requires calculating the Vmax, which is the maximum rate of conversion. The maximum rate of conversion can be defined as the product of the catalyst rate constant (Kcat) and the concentration of the enzyme.

  • Obtain rates of conversion for increasing concentrations of a substrate in a constant concentration of enzyme. Divide one by the rate of conversion for each data point to find the inverse of the rate of conversion. Find the inverse of concentration of the substrate as well.

  • Draw a graph with the y-axis representing the inverse of rate of conversion and the x-axis representing the inverse of concentration of substrate. Plot each data point as inverted above. The plot should form a straight line increasing from left to right.

  • Find the point at which the line intersects the y-axis. Divide the one by the y-value of that point. Record the result as the maximum rate of conversion or Vmax.

  • Divide the Vmax by the concentration of the enzyme. Record the result as the catalyst rate constant or Kcat.

Related Searches


  • Photo Credit tintenbild ii image by martin schmid from
Promoted By Zergnet


You May Also Like

  • How to Plot a Michaelis-Menten Curve

    Many biochemical reactions are naturally slow unless catalyzed by enzymes that increase their reaction rate. Enzyme kinetics measures the single substrate enzymatic...

  • How to Calculate Email Conversion Rates

    Your email conversion rate is a key metric and measures the percentage of successfully delivered emails that resulted in sales, signups or...

  • How to Calculate Km

    Enzymes are proteins that catalyze biochemical reactions. An enzyme interacts with a molecule, generally called a substrate, and turns it into a...

  • How to Calculate Production Rates

    A production rate measures the average time required for a manufacturing process to produce its goods.

  • How to Calculate Kcat

    In chemical reactions catalyzed by an enzyme, the enzyme lowers the amount of activation energy required by temporarily bonding with the substrate...

  • How to Calculate a Rate Constant

    Rate constants convey the speed of a reaction, letting you know how fast or slow an ingredient in the reaction will be...

  • How to Measure the Optimum Temperature for an Enzyme

    An enzyme is a protein that catalyzes (increases the rate of) chemical reactions. The optimal temperature of most enzymes, or the temperature...

  • How Do You Calculate APR?

    APR stands for annual percentage rate. It is a calculation that determines the annual interest you will pay on a loan or...

Related Searches

Check It Out

Can You Take Advantage Of Student Loan Forgiveness?

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!