bi·o·chem·is·try 
(bī′ō-kĕmĭ-strē)
(bī′ō-kĕmĭ-strē)n.
1. The study of the chemical substances and vital processes occurring in living organisms; biological chemistry; physiological chemistry.
2. The chemical composition of a particular living system or biological substance: viral biochemistry.
bi′o·chemi·cal (-ĭ-kəl) adj. & n.
bi′o·chemi·cal·ly adv.
bi′o·chemist n.