Catalysts and Enzymes

Catalysts and enzymes sound complicated, but they are really just big words for simple concepts.  Catalysts are chemicals that speed up a reaction or make it go, but are not used up in the reaction. Enzymes are catalysts in living things.

This shows the concept of how an enzyme works. The enzyme is needed to create a space for the products to be produced. The enzyme is like the key that fits in the lock. In the diagram this is shown as shapes, but in reall ife it is done through the shapes of chemical bonds, the angle at which chemicals bond to each other. Image by TimVickers, public domain.

Scientists theorize that enzymes, which are very specific to doing one job only have a “lock and key” sort of mechanism.  That is, the actual physical shape and chemical arrangement of the enzyme perfectly matches the substrate the enzyme needs to affect, so the two join up.

Catalyst Experiment 1

Pour some soda pop into a clear glass. Now scoop a tablespoon of sugar into the glass. What happens? When the pop is fizzing more, that is the carbon dioxide gas coming out of solution more quickly. The sugar acts as a catalyst and speeds up the reaction.

Catalyst Experiment 2

Pour 1/2 c. of hydrogen peroxide (H2O2) into a clear glass. Put a slice of potato into the glass. The potato bubbles and fizzes. Hydrogen peroxide plus air plus light makes water and oxygen gas. The potato doesn’t take part in the reaction, but it speeds the reaction up by acting as a catalyst.

H2O2 + air + light —> H2O + O2

Additional Layers

  • Find catalysts and enzymes around the house (laundry soap uses enzymes to break down stains; the catalytic converter in your car speeds up reaction rates and changes harmful carbon monoxide, nitrogen oxide, and hydrocarbons into carbon dioxide, water, and nitrogen, already major parts of our earth’s atmosphere; your body uses enzymes to break down your food so you can use it as fuel; yeast producing alcohol, as in bread baking, is an enzyme reaction).
  • Read more about enzymes at
  • Research how catalysts play a part in the space program by providing both water and electricity for the space shuttle astronauts.
  • Learn about Wilhelm Ostwald, the 1909 Nobel Prize winner for chemistry who worked with catalysts.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.