Enzyme Activity

European explorers had adequate knowledge, skills and equipment, but why didn't they reach the New World until the end of the 15th century? You'll be surprised to learn that the answer to this question is related to the small biological molecules called enzymes, that act as catalysts.

What is a catalyst? It is a substance that enables a reaction to occur faster, using less energy. If you plotted a graph of the energy needed for an uncatalyzed biological reaction, it would look something like this. This height represents the activation energy, which is the minimum amount of energy needed for the reaction to proceed. Enzymes, working as a catalyst, provide an alternate reaction pathway, with a lower activation energy.

So, how do enzymes actually work? Most enzymes are proteins. The part of their structure which interacts with the molecules they catalyze, is called the active site, which has affinity for only certain substrates and won't bind with others. When the correct substrates enter the active site, the enzyme changes its shape to attain a higher affinity configuration. This transition state facilitates the reaction and converts the reactants into products. The enzyme, however,