VII. SYNTHESIS OF RNA AND RIBOSOMES 



325 



^43 accounts for 2/3 of the neosome fraction resolved by chromatography 

 and ^50 accounts for 2/3 of the ribosome fraction. 



The remaining 1/3 of the ribosome fraction is clearly accounted for 

 by the 30S peak. However, this component must also include as an 

 unresolved peak the remaining 1/3 of the neosome fraction. In Fig. 20 



0.01 



0.00 



0.0001 



0.001 



TIME -T 

 (Defined by growth Q = QQe*^) 



Fig. 20. Log-log plot of the newly synthesized fraction of RNA present in total 

 cell e.xtract (#), 308 region (D), and 43S + 50S region (Q) as a function of time. 

 Data from Fig. 16. 



<^3o is compared to ^43 + 50- If the 30S and SOS ribosomes were synthesized 

 independently from a common pool of eosomes, and if the 30S peak 

 included both the neosome and the ribosome stage of synthesis, then 

 ^43+50 should be twice </)3o at all times. At early times, however, the 30S 

 component has more than its share of radioactivity. Furthermore, at 



