Why was protein considered a better candidate as the hereditary molecule than DNA?

Why was protein considered a better candidate as the hereditary molecule than DNA?

• A. Proteins had specific known functions as enzymes and structural compounds, whereas DNA had no clearly defined function.
• B. DNA was considered to be more stable as a molecule than proteins.
• C. Proteins could not carry information about hereditary traits.
• D. DNA was known to carry all genetic information from the start.

Answer: (A)

Before DNA was known to carry genetic information, scientists reasoned that the hereditary molecule should both store vast amounts of information and participate directly in cellular processes. Proteins fit this view because they already perform a wide range of specific functions: enzymes that drive reactions, structural components that give cells their shape, transport and regulatory roles, and more. The sequence of amino acids in a protein determines its three-dimensional structure and function, offering enormous diversity and a plausible way to encode detailed hereditary instructions. DNA, on the other hand, appeared chemically simple and its function was not clearly defined; the four bases and a seemingly straightforward role didn’t suggest it could carry the complex information needed for heredity. So, the idea that proteins could be the hereditary material rested on their known versatility and functional richness, contrasted with the then-perceived lack of a defined role for DNA.

Before DNA was known to carry genetic information, scientists reasoned that the hereditary molecule should both store vast amounts of information and participate directly in cellular processes. Proteins fit this view because they already perform a wide range of specific functions: enzymes that drive reactions, structural components that give cells their shape, transport and regulatory roles, and more. The sequence of amino acids in a protein determines its three-dimensional structure and function, offering enormous diversity and a plausible way to encode detailed hereditary instructions. DNA, on the other hand, appeared chemically simple and its function was not clearly defined; the four bases and a seemingly straightforward role didn’t suggest it could carry the complex information needed for heredity. So, the idea that proteins could be the hereditary material rested on their known versatility and functional richness, contrasted with the then-perceived lack of a defined role for DNA.