Enzymes are the foundation of energy and the life force in all living things. They are responsible for building, detoxifying, and healing the body. They are also the force that allows your body to digest and absorb food. Enzymes also regulate tens of thousands of other biochemical functions that take place in the body every day. Without enzymes, seeds would not sprout, fruit would not ripen, leaves would not change color, and life would not exist. Therefore, the study of enzymes has immense practical importance. Here, I begin with descriptions of the properties of enzymes and the principles underlying their catalytic power, then introduce enzyme kinetics, and end with a discussion of medical applications of enzymes.
Enzymes, most of which are proteins, are what make many of the body’s biochemical reactions possible. Actually biochemical reactions can take place without them, but at much lower rates. In fact an enzyme may cause a reaction to proceed billions of times faster than it would otherwise. Before I go on to the biochemical specifics of how this works, let me provide a figurative example. Suppose you got a bag and you put a bunch of small padlocks in it, then you put in all the keys that go with the locks. And you closed the bag and shook it hard. No matter how long you shook, chances are very small that any key would get inserted in any of the locks. But if you took them all out of the bag and this time used your hands to insert the keys in the locks, you could combine them much quicker. Enzymes act like your hands (Figure 1), quickly allowing chemical reactions that would otherwise take much longer.
Figure 1. Diagrams to show the induced fit hypothesis of enzyme action
Now, there are two reasons that enzymes are so effective at enabling biochemical reactions. First, enzymes greatly reduce the amount of energy required to start the reactions, and with less energy needed the reactions can proceed a lot faster than they could