What kind of catalysts affect biochemical reactions

The enzyme active site is the location on the enzyme surface where substrates bind, and where the chemical reaction catalyzed by the enzyme occurs. There is a precise substrate interaction that occurs at the active site stabilized by numerous weak interactions hydrogen bonds, electrostatic interactions, hydrophobic contacts, and van der Waals forces.

Enzymes form complexes with their substrates. The binding of a substrate to an enzyme active site is termed the "enzyme-substrate complex. Industrial catalysts are often metals, as most metals have a large number of electrons which are a little cavalier about exactly how close to the central atom they need to be.

This allows the metals to use these electrons to help out in reactions before claiming them back once the reaction is over. Examples are iron-based catalysts used for making ammonia the Haber-Bosch process and the nickel catalysts used for making saturated fats.

Biological catalysts work on a very different principle. Rather than being metals with fast-and-loose electrons, biological catalysts are large complex molecules called enzymes, which contain specific pockets for the reactants to fit into.

Once they are trapped inside the enzyme aids the reaction, either by forming temporary bonds with the reactants to help them fit together, or by simply holding them close enough to each other to actually react and form the product.

Most enzymes are found inside organic lifeforms, which means that they do not need high temperatures to function while metal catalysts tend to need a bit of an energy kick to get going. In fact enzymes will denature, or break, if heated up too far beyond their optimum temperature for most around 40 degrees, although some bacterial enzymes can work at degrees. In some cases, such as in biological washing powders, this can be a huge benefit as it means less energy is needed for the reaction and the clothes can be washed at lower temperatures.

In some industrial processes, however, high temperatures are needed to increase the rate of reaction so cooling everything down to 40 degrees is impractical. Another important point about enzymes is that unlike the metal catalysts they are incredibly specific.

As the reactants fit into pockets inside the enzyme each enzyme can only fit the molecules it's meant to be catalysing. And as enzymes are large and complex molecules it's not so simple to just design them to fit the reactants you need.

Again, this is fine for biological washing powders, as there are plenty of enzymes that have evolved to break down egg stains, blood stains, and form strange little bobbles on jumpers. For chemical processes it can be a bit more difficult - not many organisms have evolved to remove the toxic gases from petrol, or synthesise sulfur dioxide.

Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:. Skip to main content. Chemical Kinetics. Search for:. Enzyme Catalysis. Learning Objective List the five typical mechanisms used by enzymes to catalyze biological reactions.