The Structure of DNA

Section 2: The Structure of DNA

After confirming that DNA is the genetic material of organisms, scientists were eager to understand how DNA stores genetic information and how it determines biological traits. To answer these questions, it was first necessary to clarify the structure of DNA.

Construction of the DNA Double Helix Model

In the quest to uncover the structure of DNA, the ultimate breakthrough came in 1953, achieved by two young scientists—American biologist James D. Watson (1928-) and British physicist Francis Crick (1916-2004). Their revelation of the DNA double helix structure was a groundbreaking discovery of the era and a milestone in the development of biology.

Structure of DNA

The main features of the DNA double helix structure (Figure 3-8) are as follows:

1. DNA is composed of two single strands that twist around each other in an antiparallel fashion to form a double helix structure.
2. Deoxyribose and phosphate in DNA alternate and link together, forming the backbone on the outside of the helix, while the bases are arranged on the inside.