Crick and Watson contributed to understanding which macromolecule's structure?

Crick and Watson contributed to understanding which macromolecule's structure?

• A. Protein
• B. DNA
• C. Lipids
• D. Carbohydrates

Answer: (B)

The fundamental idea here is the structure of DNA, the macromolecule that carries genetic information. Crick and Watson proposed the double-helix model, showing DNA as two long strands wound around each other with a sugar-phosphate backbone on the outside and bases paired inside. The base pairing—adenine with thymine, and cytosine with guanine—via hydrogen bonds explains how the two strands fit together and, crucially, how information can be accurately copied: each strand can serve as a template for the other during replication, leading to semiconservative replication. The strands are antiparallel, running in opposite directions, which aligns the base pairs inside the helix and stabilizes the structure. This understanding clarified why DNA can store vast amounts of information and be faithfully transmitted from cell to cell and generation to generation. It also laid the groundwork for how mutations can occur and how genetic information is read and used to produce proteins. Proteins, lipids, and carbohydrates are important macromolecules in biology, but Crick and Watson’s landmark contribution was specifically the structure of DNA, not the structures of those other biomolecules.

The fundamental idea here is the structure of DNA, the macromolecule that carries genetic information. Crick and Watson proposed the double-helix model, showing DNA as two long strands wound around each other with a sugar-phosphate backbone on the outside and bases paired inside. The base pairing—adenine with thymine, and cytosine with guanine—via hydrogen bonds explains how the two strands fit together and, crucially, how information can be accurately copied: each strand can serve as a template for the other during replication, leading to semiconservative replication. The strands are antiparallel, running in opposite directions, which aligns the base pairs inside the helix and stabilizes the structure.

This understanding clarified why DNA can store vast amounts of information and be faithfully transmitted from cell to cell and generation to generation. It also laid the groundwork for how mutations can occur and how genetic information is read and used to produce proteins.

Proteins, lipids, and carbohydrates are important macromolecules in biology, but Crick and Watson’s landmark contribution was specifically the structure of DNA, not the structures of those other biomolecules.