Enzyme Reaction Rate Calculator
1. Basic Velocity Calculation (Product/Time)
Calculate the rate of reaction based on the change in product concentration over time.
2. Michaelis-Menten Velocity
Predict the reaction rate using the Michaelis-Menten equation.
How to Calculate Enzyme Reaction Rate
Enzyme kinetics is the study of the chemical reactions that are catalyzed by enzymes. Understanding the reaction rate is crucial for biochemistry, pharmacology, and industrial fermentation. The reaction rate (or velocity) represents how quickly an enzyme converts a substrate into a product.
The Basic Rate Formula
In the simplest laboratory setup, you measure the appearance of a product over a specific timeframe. The formula is:
Rate (v) = Δ[P] / Δt
Where:
- Δ[P]: The change in product concentration.
- Δt: The time interval.
The Michaelis-Menten Equation
When studying how the rate changes relative to the amount of substrate available, we use the Michaelis-Menten model. This is the standard model for single-substrate enzyme kinetics:
v = (Vmax * [S]) / (Km + [S])
Key terms defined:
- v: The initial reaction velocity.
- Vmax: The maximum velocity achieved by the system, happening at saturating substrate concentrations.
- [S]: The concentration of the substrate.
- Km (Michaelis Constant): The substrate concentration at which the reaction velocity is half of Vmax. It indicates the affinity of the enzyme for the substrate.
Practical Example
Imagine you have an enzyme with a Vmax of 100 μM/min and a Km of 2 mM. If you provide a substrate concentration [S] of 2 mM, the calculation would be:
v = (100 * 2) / (2 + 2) = 200 / 4 = 50 μM/min
In this case, because [S] equals Km, the rate is exactly half of Vmax.