VII. SYNTHESIS OF RNA AND RIBOSOMES 



301 



TABLE I 

 RNA Content of Ribosomes 



different species; the reported variations may be due to variable 

 contamination, 



Ribosomes of different sedimentation constants appear to have the 

 same protein/nucleic acid ratio. Figure 5 shows the correspondence be- 

 tween the protein (measured by S^'') and the nucleic acid (measured by 



.300 



o 



CD 



d 



200 



.100 



LLr-i II 



80 



50 1= 



OC 



8 12 16 20 



Fraction number 



Fig. 5. Sedimentation analj-sis of a ribosome pellet shows correspondence be- 

 tween nucleic acid content indicated by optical density (O.D.), protein indicated 

 by S", and peptidase activity. 



