The key difference between catalyst and inhibitor is that a catalyst increases the rate of a reaction, whereas inhibitor stops or decreases the rate of a reaction.
Catalysts and inhibitors are chemical compounds. These two groups of compounds show opposite activity in biological and chemical systems. They participate in chemical reactions but are not consumed.
CONTENTS
1. Overview and Key Difference
2. What is Catalyst
3. What is Inhibitor
4. Side by Side Comparison – Catalyst vs Inhibitor in Tabular Form
5. Summary
What is Catalyst?
Catalyst is a chemical compound that can increase the rate of a reaction without itself being consumed. Therefore, this compound can continue to act repeatedly. Due to this reason, only a small amount of catalyst is required for a certain chemical reaction.
Figure 01: Effect of a Catalyst on a Chemical Reaction
The catalyst provides an alternative pathway for a chemical reaction by reducing the activation energy of a reaction. Here, the catalyst combines with the reactant to create an intermediate product, and after the completion of the required reaction, the catalyst leaves the intermediate and regenerates.
There are two types of catalysts as homogeneous and heterogeneous catalysts. In homogeneous catalysts, the molecules are in the same phase as reactant molecules. However, in heterogeneous catalysts, the molecules are in a different phase to that of reactant molecules. Enzymes are a good example of biological catalysts.
What is Inhibitor?
An inhibitor is a chemical compound that can either stop or decrease the reaction rate of a chemical reaction. Therefore, we call them “negative catalysts”. Moreover, this compound can reduce the activity of a catalyst as well.
Figure 02: Competitive and Non-Competitive Inhibitors for Enzymes
Unlike catalysts, these compounds do not provide a reaction pathway to reduce the activation energy. The role of an inhibitor is to either deactivate the catalyst or to remove reaction intermediates.
What is the Difference Between Catalyst and Inhibitor?
Catalyst is a chemical compound that can increase the rate of a reaction without being consumed while Inhibitor is a chemical compound that can either stop or decrease the reaction rate of a chemical reaction. So, this is the key difference between catalyst and inhibitor.
Moreover, catalysts work by providing an alternative reaction pathway by producing a reaction intermediate while inhibitors work by either deactivates the catalyst or removes the reaction intermediates.
Below infographic summarizes the difference between catalyst and inhibitor.
Summary – Catalyst vs Inhibitor
Catalyst is a chemical compound that can increase the rate of a reaction while inhibitor is a chemical compound that can either stop or decrease the reaction rate of a chemical reaction. The key difference between catalyst and inhibitor is that a catalyst increases the rate of a reaction, whereas inhibitor stops or decreases the rate of a reaction.
Reference:
1. “Catalyst.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 15 Aug. 2019, Available here.
Image Courtesy:
1. “Catalysis- Reaction progress” By Smokefoot – Wikimedia Commons (CC0) via Commons Wikimedia
2. “Enzyme inhibition” By California16 – Own work (CC BY-SA 4.0) via Commons Wikimedia