Lock and Key Model

Now that the primary, secondary, and tertiary structure of proteins have been discussed we can think about the shape of the molecule. Because of interactions between atoms within them, the molecules are often bent and twisted. This complicated structure gives each protein a specific shape. Because of the shape, the molecule can interact in very specific ways with other molecules. Think of a jigsaw puzzle. There is only one piece that will fit perfectly in each spot.

One model used to describe the behavior of molecules interacting because of their shapes is the lock and key model. The lock may represent a molecule in a cancerous cell, while the keys represent different drug molecules that will be tested to see if the cancer can be weakened or destroyed. Click on the key that fit the lock.

Unfortunately, it is much harder for a chemist to design a drug that fits than it is to illustrate the lock and key model.

Things to Think About