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

50S 30S

O

Incoming

ribosomal

subunits

,,/

50S 30S

Growing

polypeptide

chains

~

Complete

peptide

chain

FIGURE 97. A polyribosome. A single

strand of mRNA passes through one ribo-

some after another, like one tape passing

through several tape recorders in a row.

The result is a set of growing proteins in

various stages of completion: the analogue

to a musical canon produced by the

staggered tape recorders. [From A.

Lehninger, Biochemistry.]