Q. 17.24 - An Introduction to General, Organic, and Biological Chemistry

Question

What is meant by double helix?

Step-by-Step Solution

Answer

     The look of double-stranded $\mathrm{DNA}$ is described by the double helix, which is made up of two linear strands that run in opposite directions, or anti-parallel, and twist together. Within the double helix, each $\mathrm{DNA}$ strand is a long, linear molecule made up of smaller units called nucleotides that link together to form a chain.

Step 1: Given Information

     A double-stranded $\mathrm{DNA}$ molecule's molecular form is described by the double helix. Francis Crick and James Watson published the first description of $\mathrm{DNA}\text{'}\mathrm{s}$ molecular structure, which they named a "double helix," in the magazine Nature in $1953$ . Watson, Crick, and their colleague Maurice Wilkins were awarded the Nobel Prize in Physiology or Medicine in $1962$ for this groundbreaking discovery. Rosalind Franklin, who was not recognized at the time, contributed a critical input that enabled this discovery. Crick stated after her death that her participation was crucial.

Step 2: Explanation

     The look of double-stranded $\mathrm{DNA}$ is described by the double helix, which is made up of two linear strands that run in opposite directions, or anti-parallel, and twist together. Within the double helix, each $\mathrm{DNA}$ strand is a long, linear molecule made up of smaller units called nucleotides that link together to form a chain

Step 3: Conclusion

     Sugar and phosphate molecules are joined by chemical bonds to form the chemical backbones of the double helix, which are known as sugar-phosphate backbones. The two helical strands are linked through interactions between nucleotide pairs, commonly known as base pairs. Base pairing occurs in two ways: nucleotide $\mathrm{A}$ pairs with $\mathrm{T}$and nucleotide $\mathrm{C}$ couples with $\mathrm{G}$.