The key difference between catalyst and inhibitor is that catalysts and inhibitors have opposite effects on reaction rates. Catalysts increase reaction rates, while inhibitors decrease them.
What is Catalyst?
A catalyst is a substance that increases the rate of a chemical reaction by providing an alternative reaction pathway with lower activation energy, without itself undergoing any permanent chemical changes.
It facilitates the reaction by interacting with the reactants to lower the energy barrier for the formation of products, allowing the reaction to proceed more quickly or at lower temperatures.
What is Inhibitor?
An inhibitor is a substance or agent that interferes with or blocks the activity of a biological or chemical process. In various contexts, inhibitors can prevent or reduce the rate of a specific reaction or function. They are used in medicine, biochemistry, and other scientific fields to control or regulate certain processes.
In pharmacology, for example, inhibitors are often used as drugs to target enzymes or proteins involved in disease pathways. By inhibiting these specific targets, drugs can slow down or stop the progression of certain diseases.
In biochemistry, enzyme inhibitors are molecules that bind to an enzyme’s active site or other regions, preventing the enzyme from catalyzing its reaction. This can be beneficial in controlling metabolic pathways or studying enzyme functions.
In general, inhibitors play a crucial role in understanding and manipulating various biological and chemical processes for both research and therapeutic purposes.
Catalyst vs Inhibitor:
The key difference between catalyst and inhibitor is given below:
| Catalysts | Inhibitors | |
| Definition | Substances that speed up chemical reactions by lowering the activation energy without being consumed in the process. | Substances that slow down or prevent chemical reactions by interfering with the catalyst or essential reactants. |
| Effect on Reaction Rate | Increase the reaction rate by providing an alternative pathway with lower activation energy. | Decrease the reaction rate by interfering with the reactants or catalysts, raising the activation energy, or blocking active sites. |
| Consumption | Not consumed in the reaction, similar to catalysts, can inhibit multiple reactions with a small amount. | Not consumed in the reaction, similar to catalysts, and can inhibit multiple reactions with a small amount. |
| Reactivity | Do not change the equilibrium position or alter the overall energy change of the reaction. | Do not change the equilibrium position or alter the overall energy change of the reaction. |
| Mechanism | Catalysts provide an alternative reaction pathway with lower activation energy, allowing reactants to reach the transition state more easily. | Inhibitors interfere with the catalyst or reactants by binding to the active site, blocking it, or altering the reactant’s shape or concentration. |
| Types | Can be classified as homogeneous (in the same phase as reactants) or heterogeneous (in a different phase than reactants). | Can be classified as competitive inhibitors, non-competitive inhibitors, uncompetitive inhibitors, or mixed inhibitors. |
| Effects on Equilibrium | No direct effect on the position of the equilibrium in a reversible reaction. | No direct effect on the position of the equilibrium in a reversible reaction. |
| Examples | Enzymes, transition metal complexes, and acid/base catalysts. | Drugs, poisons, corrosion inhibitors, and enzyme inhibitors. |