What is the used to demonstrate that the DNA molecule is a helix?
To demonstrate that the DNA molecule is a helix, one commonly used method is X-ray crystallography. This technique allows scientists to study the arrangement of atoms within a crystal structure. Here's how it works:
1. First, DNA molecules are extracted and purified.
2. These purified DNA molecules are then carefully crystallized. Crystallization is the process of arranging molecules in a repetitive and ordered pattern.
3. X-ray beams are directed at the DNA crystal. The X-rays interact with the electrons in the crystal, causing them to scatter.
4. The scattered X-rays are captured on a detector, forming a diffraction pattern.
5. The diffraction pattern contains information about the arrangement of atoms within the crystal, including the helical nature of the DNA molecule.
6. Finally, using various mathematical algorithms and calculations, scientists can analyze the diffraction pattern to determine the structure and helical nature of the DNA molecule.
Through X-ray crystallography, scientists such as James Watson and Francis Crick were able to determine the double helical structure of DNA in 1953, leading to significant advancements in our understanding of genetics.