438 CHAPTER 47 



Novelli, G. D., Kameyama, F., and Eisenstadt, J. M., "The Effect of Ultraviolet Light and 

 X Rays on an Enzyme-Forming System," J. Cell. Comp. Physiol., 58 (Suppl.) :225-244, 

 1961. 



Schulman, H. M., and Bonner, D. M., "A Naturally Occurring DNA-RNA Complex from 

 Neurospora crassa" Proc. Nat. Acad. Sci., U.S., 48:53-63, 1962. 



Speyer, J. F., Lengyel, P., Basilio, C, and Ochoa, S., "Synthetic Polynucleotides and the 

 Amino Acid Code, II," Proc. Nat. Acad. Sci., U.S., 48:63-68, 1962. 



Stevens, A., "Net Formation of Polyribonucleotides with Base Compositions Analogous to 

 Deoxyribonucleic Acid," J. Biol. Chem., 236 (No. 7), PC 44, 1961. 



Strauss, B. S., An Outline of Chemical Genetics, Philadelphia, Saunders, 1960. 



Tal, M., and Elson, D., "The Reversible Release of Protein, Ribonucleic Acid and Deoxy- 

 ribonuclease from Ribosomes," Biochim. et Biophys. Acta, 53:227-229, 1961. 



Zamecnik, P. C, "The Microsome," Scient. Amer., 198 (No. 3) :1 18-124, 1958. 



Zamecnik, P. C, "Historical and Current Aspects of the Problem of Protein Synthesis," 

 Harvey Lect., 54:256-281, 1960. 



QUESTIONS FOR DISCUSSION 



47.1. Would you expect the RNA code for amino acids to be the same in all free-living 

 organisms? Explain. 



47.2. Compare the replication of RNA virus with that of polypeptide chains. 



47.3. If a polypeptide chain is specified by a sequence 2000 or so nucleotides, what would 

 you conclude regarding the presence of non-nucleotide material as punctuation 

 between cistrons? 



47.4. To what use can you put the fact that the spacing between nucleotides in a DNA chain 

 is nearly the same as it is between amino acids in a polypeptide chain? 



47.5. Discuss the hypothesis that ribosomes are viruses. 



47.6. Make a report on advances in our understanding of the genetic code since the present 

 account was written (February 1962). 



47.7. What evidence can you present that the attachment of messenger RNA to the ribosome 

 does not involve extensive complementary base pairing? 



47.8. Give evidences that messenger RNA is single-stranded. 



