Question

A cell biologist isolates a protein-RNA complex that exhibits catalytic activity. Treatment of this complex with RNase completely abolishes catalytic activity. However, treatment of the complex with proteases results in only a 15% decrease in catalytic activity. Which of the following is the most likely explanation for these data?
A. The catalytic activity of the complex is enhanced by the protein component and completely dependent on the RNA component of the complex.
B. The catalytic activity of the complex is independent of the protein component and only enhanced by the RNA component of the complex.
C. The catalytic activity of the complex is completely dependent on the protein component and only enhanced by the RNA component of the complex.
D. The catalytic activity of the complex is enhanced by the protein component and enhanced by the RNA component of the complex.

Answer 1

Answer:

A. The catalytic activity of the complex is enhanced by the protein component and completely dependent on the RNA component of the complex.

Explanation:

RNAses are enzymes that degrade RNA. When treating the complex with an RNAse, the catalytic activity is completely abolished. This tells us that the RNA component is indispensable to the catalytic activity of the complex.

Proteases are enzymes that degrade proteins. Treating the complex with proteases only decreases slightly the catalytic activity, but it does not abolish it completely. This tells us that the protein component of the complex enhances the catalytic activity, but without it the complex can still work.