Poly U, an artificial mRNA, was added to a test tube with all other components for protein synthesis (“Complete system”). Other test tubes differed from the complete system as indicated in the table. Samples were tested for radioactive phenylalanine incorporation. with the results in the table below. Explain the results for EACH of the conditions.

Condition | Radioactivity in protein
complete system | 29,500
Minus poly U mRNA | 70
Minus ribosomes | 52
Minus ATP | 83
Plus RNase (hydronlyzes RNA) | 120
Plus DNase | 27,600
Radioactive glycine instead of phenylalanine | 33
Mixture of 19 radioactive amino acids minus phenylalanine | 276