Enzymes

5.1 Enzyme Action

Enzymes are biological catalysts. This means they speed up chemical reactions in living organisms without being consumed in the process. They are typically proteins, and their specific three-dimensional structure is crucial for their function.

Key Concepts

• Substrate: The molecule(s) upon which an enzyme acts.
• Active Site: A specific region on the enzyme where the substrate binds.
• Enzyme-Substrate Complex: The temporary association between the enzyme and its substrate.
• Product: The molecule(s) that are formed as a result of the enzyme-catalyzed reaction.

How Enzymes Work

Enzymes work by lowering the activation energy of a reaction. The activation energy is the minimum amount of energy required to start a chemical reaction.

The enzyme has a unique three-dimensional shape with a specific region called the active site. This active site is complementary in shape and chemical properties to the substrate. When the substrate binds to the active site, an enzyme-substrate complex is formed.

Within the enzyme-substrate complex, the enzyme helps to convert the substrate(s) into product(s). The substrate binds to the active site through various weak bonds, such as hydrogen bonds and ionic bonds.

Once the product(s) are formed, they are released from the active site, and the enzyme is free to catalyze another reaction.

Diagram

Table Summary

Concept	Description
Substrate	The molecule(s) that the enzyme acts upon.
Active Site	The specific region on the enzyme where the substrate binds.
Enzyme-Substrate Complex	The temporary association between the enzyme and its substrate.
Product	The molecule(s) formed as a result of the enzyme-catalyzed reaction.