How do enzymes act as biological catalysts?

Enzymes act as biological catalysts by speeding up chemical reactions in the body without being consumed in the process.

Enzymes are proteins that are found in all living cells. They play a crucial role in the body's metabolic processes, acting as catalysts to speed up chemical reactions that would otherwise occur too slowly to sustain life. They do this by lowering the activation energy of the reactions, which is the minimum amount of energy required for the reaction to occur.

The way enzymes work is fascinating. Each enzyme has a specific shape and structure that allows it to bind with a particular molecule, known as the substrate. The part of the enzyme where the substrate binds is called the active site. The active site and the substrate fit together like a lock and key, a concept known as the 'lock and key' model. This specific interaction ensures that enzymes can only catalyse specific reactions, contributing to the regulation of metabolic pathways.

When the substrate binds to the enzyme's active site, it forms an enzyme-substrate complex. This interaction changes the shape of the substrate, breaking existing bonds and forming new ones. This process transforms the substrate into a new molecule, known as the product. Once the reaction is complete, the product is released, and the enzyme is free to catalyse another reaction.

It's important to note that enzymes are not consumed or changed in the reaction. They can be used repeatedly to catalyse the same reaction, making them highly efficient. However, they can be affected by factors such as temperature and pH. If conditions are too extreme, enzymes can lose their shape and become denatured, losing their catalytic ability.

In summary, enzymes are biological catalysts that speed up chemical reactions in the body by lowering the activation energy and providing a specific site for the reaction to occur. They are essential for life, enabling the complex web of metabolic reactions that sustain us.