  Replication of DNA and synthesis of proteins are studied from the view-point
of quantum database search. Identification of a base-pairing with a quantum
query gives a natural (and first ever) explanation of why living organisms have
4 nucleotide bases and 20 amino acids. It is amazing that these numbers arise
as solutions to an optimisation problem. Components of the DNA structure which
implement Grover's algorithm are identified, and a physical scenario is
presented for the execution of the quantum algorithm. It is proposed that
enzymes play a crucial role in maintaining quantum coherence of the process.
Experimental tests that can verify this scenario are pointed out.
