Question

In what way was Chargaff's rule an essential part of Watson and Crick's discovery of the double helix structure?

Short answer

Answer: Chargaff's rule played a crucial role in Watson and Crick's discovery of the double helix structure of DNA by providing the basis for understanding the pairing between the nitrogenous bases, A-T and G-C. These complementary base pairs explained how genetic information could be preserved and replicated, allowing Watson and Crick to propose the double helix DNA structure.

Step-by-step solution

Explain Chargaff's rule

Chargaff's rule states that in any given organism's DNA, the quantity of adenine (A) is approximately equal to the quantity of thymine (T), and the quantity of cytosine (C) is approximately equal to the quantity of guanine (G). This rule describes that A-T and G-C form pairs which are complementary to each other in the DNA structure.

Discuss Watson and Crick's discovery of the double helix structure

Watson and Crick proposed the double helix model of the DNA structure in 1953. In their model, they described that DNA consists of two chains of nucleotides running in opposite directions, forming a ladder-like structure. These chains are held together by hydrogen bonds between the bases of the nucleotides, specifically between A-T and G-C bases. This structure allows for effective and accurate replication of genetic information during cell division.

Explain the role of Chargaff's rule in Watson and Crick's discovery

Chargaff's rule played a crucial role in the discovery of the double helix structure of DNA by Watson and Crick. It provided the basis for understanding the pairing between the nitrogenous bases, which helped them figure out that A-T and G-C form bonded pairs in the DNA structure. These complementary base pairs explained how the genetic information could be preserved and replicated as each strand could serve as a template to reproduce the other. Therefore, Chargaff's rule was an essential component in understanding and proposing the biochemical nature of the double helix DNA structure.