Gödel, Escher, Bach An Eternal Golden Braid by Douglas R. Hofstadter

The Genetic Code.

u C A G

phe ser tyr cys V

U

phe ser tyr cys C

leu ser punc. punc. A

leu ser punc. trp G

leu pro his arg V

leu pro his arg C

C

leu pro gin arg A

leu pro gin arg G

ile thr asn ser V

ile thr asn ser C

A ile

thr , Iys arg A

met thr Iys arg G

val ala asp gly V

val ala asp gly C

G val ala glu gly A

val ala glu gly G

FIGURE 94. The Genetic Code, by which each triplet in a strand of messenger RNA codes
for one of twenty amino acidl (or a punctuation mark).

Reductionistic Explanation of Protein Function

Another discrepancy between Typogenetics and true genetics-and this is
probably the most serious one ofall--is this: whereas in Typogenetics, each
component amino acid of an enzyme is responsible for some specific "piece
of the action", in real enzymes, individual amino acids cannot be assigned
such clear roles. It is the tertiary structure as a whole which determines the
mode in which an enzyme will function; there is no way one can say, "This

(^520) Self-Ref and Self-Rep