How do enzymes act as catalysts in metabolic reactions?

Enzymes act as catalysts in metabolic reactions by speeding up the rate of these reactions without being consumed.

Enzymes are biological catalysts, which means they increase the speed of chemical reactions in the body without being used up or changed in the process. They do this by lowering the activation energy required for a reaction to occur. Activation energy is the minimum amount of energy needed for reactants to form products in a chemical reaction. By reducing this energy barrier, enzymes make it easier for the reaction to take place, thus speeding up the rate of the reaction.

Enzymes are proteins that are specifically shaped to fit certain molecules, known as substrates. The part of the enzyme where the substrate binds is called the active site. The active site and the substrate complement each other in such a way that they fit together like a lock and key. This specific interaction ensures that the enzyme can catalyse its reaction efficiently.

When a substrate enters the active site of an enzyme, it forms a temporary structure called an enzyme-substrate complex. This complex lowers the activation energy of the reaction by positioning the substrate in a way that makes the reaction more likely to occur. The enzyme may also stress the bonds in the substrate, making it easier for them to break and new ones to form. Once the reaction has taken place, the products are released and the enzyme is free to catalyse another reaction.

Enzymes are crucial for life as they allow metabolic reactions to occur at a rate fast enough to sustain life. Without enzymes, these reactions would occur too slowly or not at all, and life as we know it would not be possible. They are involved in a wide range of processes, from digestion to DNA replication, and their activity can be influenced by various factors, including temperature, pH, and the presence of inhibitors or activators.