What is an enzyme? What is meant by the specificity of an enzyme? Explain how the Active Site Theory may be used to explain the specificity of enzymes - Leaving Cert Biology - Question 14(b) - 2010

The specificity of an enzyme refers to its ability to act only on a particular substrate. This means that each enzyme is tailored to catalyze a specific reaction and will not react with other substrates.

The Active Site Theory posits that the region of the enzyme where the substrate binds—called the active site—has a unique shape that matches the substrate. When the substrate enters the active site, the enzyme undergoes a conformational change, facilitating the formation of the enzyme-substrate complex. This specific interaction ensures that enzymes finely regulate biochemical reactions by only interacting with their corresponding substrates.

The term immobilisation refers to the process of attaching enzymes to an inert substance or fixing them to each other, thus restricting their movement. This allows for repeated use of enzymes in various applications.

A bioreactor is a vessel in which products are made by cells or organisms. It provides the necessary environment for biochemical processes, ensuring optimal conditions for growth and activity of the microorganisms or cells involved.

One example is the use of glucose isomerase, which converts glucose (substrate) into fructose (product) in a bioreactor setup. The enzyme is immobilised on a suitable support to allow for continuous operation and easy separation of products.