The field of biochemistry covers all of the individual jobs that cells must do to keep the body functioning. This includes turning food into fuel, and using the fuel for whatever is needed.
The hprt gene directs the production of a protein known as HPRT. Studies in biochemistry have shown that the job of HPRT is to recycle certain chemicals in the body known as purines. These purines are important for the life and operations of every cell in the body.