The study of protein synthesis often uses a cell-free system

The study of protein synthesis often uses a cell-free system where cells are ground with an abrasive to release the cell contents and then filtered to remove the abrasive. These materials are added to the system, generating the indicated results:
Materials Added Results
Radioactive amino acids Radioactive protein produced
Radioactive amino acids No radioactive protein produced and RNase (an RNA-digesting enzyme)
What is the best interpretation of these observations?