Changes

For drugs to act upon the body they must be able to exert some chemical influence upon a cell to result in a physiological response. They are capable of doing this by binding to a target molecule (usually proteins).

For drugs to act upon the body they must be able to exert some chemical influence upon a cell to result in a physiological response. They are capable of doing this by binding to a target molecule (usually proteins).

There are four main kinds of targets for the drugs to bind to:

There are four main targets which drugs to bind to:

* '''Receptors''' - these are protein molecules that are capable of responding to endogenous chemical signals. They are usually found on the cell membrane, in the cytoplasm or on the nucleus and other organelles.

* '''Receptors''' - these are protein molecules that are capable of responding to endogenous chemical signals. They are usually found on the cell membrane, in the cytoplasm or on the nucleus and other organelles.