The Collaborative International Dictionary of English v.0.48:

biosynthesis \biosynthesis\ n.
   1. production of a chemical compound by a living organism.

   Syn: biogenesis.
        [WordNet 1.5]

   2. the production of chemical substances by use of reagents
      or enzymes derived from living organisms, in reactions
      modeled on those observed in living organisms.
      [PJC]

WordNet (r) 3.0 (2006):

biosynthesis
    n 1: production of a chemical compound by a living organism
         [syn: biosynthesis, biogenesis]