Environmental Impacts on Enzyme Function

Enzyme Structure and Function

Enzymes are proteins that act as biological catalysts, speeding up chemical reactions within cells.
They work by temporarily binding to a substrate and lowering the activation energy required for the reaction, which makes the reaction faster.
This temporary binding occurs at the enzyme’s active site, a specially shaped area where the substrate fits.

Temperature and Enzyme Function

Each enzyme has an optimum temperature at which it works best. Generally, as temperature increases, so does the reaction speed, up to the enzyme’s optimum temperature.
Beyond this point, however, the enzyme can become ‘denatured’, meaning its structure (and therefore function) is irreversibly damaged due to the breaking of hydrogen bonds.
Once an enzyme is denatured, it can’t perform its function and the reaction speed decreases.

pH and Enzyme Function

Similar to temperature, enzymes have an optimum pH level. While pH affects the charge of the amino acids at the active site, it also affects the shape of the enzyme and substrate.
At a pH above or below the optimum, the shape of the enzyme’s active site can change, preventing the substrate from binding and therefore slowing the reaction.
In extreme conditions, the enzyme can also become denatured.

Enzyme Concentration and Enzyme Function

Increasing the concentration of enzymes will increase the reaction speed, as more enzymes mean more reactions can occur simultaneously.
However, if the substrate concentration is low, having more enzymes won’t increase the reaction rate, as there won’t be enough substrates for the extra enzymes to work on.

Substrate Concentration and Enzyme Function

If the concentration of the substrate increases, the reaction rate also increases until all of the enzymes’ active sites are occupied.
Beyond this point, adding more substrate won’t increase the rate of reaction since there are no additional active sites available to bind to the substrates.

Impact of Inhibitors

Inhibitors are substances that can reduce the rate of enzyme reactions. They can be competitive (competing with the substrate for the active site) or non-competitive (binding to a different part of the enzyme, changing its shape and preventing the substrate from binding).
Inhibitors can be used by cells to regulate enzyme activity and prevent over-production of certain products.

Influence of Activators

Some molecules, known as activators, enable or increase enzyme activity. They can bind to enzymes and change their shape, making it easier for the substrate to bind to the active site, enhancing reaction rate.

Environmental Manipulation and Enzyme Function

In many industrial and biotechnological applications, enzyme function is optimised by manipulating environmental conditions. For example, enzymes in detergents are modified to function best at high temperatures and pH levels typical of washing machine cycles.
Understanding the impacts of environmental factors on enzyme function allows scientists and industry professionals to optimise processes for efficiency and productivity.