In 1944 Avery, MacLeod, and McCarty performed transformation experiments using live, harmless bacteria and extracts from virulent bacteria treated with various enzymes. Which of the following enzymes were used and why? (A) Proteases and RNases to rule out protein and RNA as the transforming factors (B) Lipase (an enzyme that facilitates the breakdown of lipids) to rule out lipoproteins as the transforming factor (C) Kinase (an enzyme that facilitates transfer of a phosphate group from ATP to a substrate molecule) to show that transformation is phosphorylation dependent (D) ATPase to show that transformation is not dependent on ATP

Option-A

Explanation:

Avery, MacLeod, and McCarty performed the experiment on the strains of S. pneumoniae used by the Griffith in the reformation experiment.

To know the chemical nature of the transforming principle which was expected to be a protein at that time, the solution was treated with a variety of biomolecule degrading enzyme-like RNases, DNases and proteases.

They found that the treatments with proteases and RNases has no effect on the process of transformation but the treatment with DNAses has stopped the process of transformation as it degraded the transforming principle and confirmed that DNA is the transforming material and is the heredity material.

Thus, Option-A is the correct answer.