DNA Structure

In 1953, scientists James Watson and Francis Crick made a groundbreaking discovery. Using Rosalind Franklin's X-ray images, they described the structure of DNA or Deoxyribonucleic acid.

DNA has a double-helical structure, resembling a spiral staircase.

The sides consist of sugar and phosphate molecules, while the steps consist of nitrogenous base pairs: adenine pairs with thymine, and guanine pairs with cytosine.

DNA’s two strands run in opposite directions, forming an antiparallel structure.

Hydrogen bonds between base pairs link the strands, holding the structure together like the stairs of a ladder.

Surprisingly, the total DNA length in a single human cell stretches up to two meters—about the height of a camel.

But how does such long DNA fit inside a tiny nucleus? Nature has an ingenious solution. DNA strands are tightly wound and compacted like a tightly wound spring, allowing them to occupy a small space.