Biochemistry is the study of the metabolism of cells.

Early work by Buchner and Pasteur showed the importance of enzymes in microbial metabolism, but most scientists believed that microbial metabolism was not related to that of plants and animals.

Kluyver (1888-1956) and van Niel (1897-1985) demonstrated that all living things share basic metabolic reactions involving energy harvest from foods.  Their work would lead to the modern study of biochemistry.

Basic biochemical research is used in many practical applications, including:

Agriculture - development of non-persistant pesticides.

Medicine - monitoring of the physiology of patients when diagnosing illness and during the course of treatment, treatment for metabolic diseases such as phenylketonuria (PKU, the inability to metabolize phenylalanine) and the development of new drugs for the treatment of diseases.