1E6 to 1E7 Ribosomes/cell
||Robert A. Freitas Jr., Ralph C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004. Link - link 2nd paragraph
|| Benjamin Lewin, Genes V, Oxford University Press, New York, 1995.
||2nd paragraph: "The best-known biological example of such molecular machinery is the ribosome, the only programmable nanoscale positional assembler currently in existence.* Numbering ~10^6-10^7 units per living eukaryotic cell and ~20,000 units per prokaryotic (bacterial) cell [primary source], ribosomes act as general-purpose factories building diverse varieties of proteins by bonding amino acids together in precise sequences under instructions provided by a strand of messenger RNA (mRNA) copied from the host DNA (Figure 4.7), with energy for ribosome movement along the mRNA tape provided by the hydrolysis of guanosine triphosphate (GTP) [primary source]." Better ref required