What is the name of the sugar molecule in the DNA helix?
The correct answer and explanation is:
The sugar molecule in the DNA helix is called deoxyribose.
Deoxyribose is a five-carbon sugar that is a key component of the DNA backbone. The name “deoxyribose” is derived from the fact that it is similar to ribose, the sugar found in RNA, but it lacks one oxygen atom. Specifically, in deoxyribose, the second carbon atom has a hydrogen atom instead of a hydroxyl group (–OH) that is present in ribose. This small structural difference plays an essential role in the stability of DNA.
The deoxyribose sugar molecules are linked together by phosphodiester bonds to form the long chains that make up the backbone of the DNA strand. These sugar-phosphate backbones are essential for maintaining the structure and integrity of the double helix. The deoxyribose molecules alternate with phosphate groups, which help to link the nucleotides (the basic units of DNA) into a continuous chain.
Each nucleotide in DNA consists of three components: a phosphate group, a deoxyribose sugar molecule, and a nitrogenous base (adenine, thymine, cytosine, or guanine). The nitrogenous bases pair with each other across the two strands of the DNA helix, forming the “rungs” of the ladder-like structure, while the deoxyribose and phosphate form the “sides” of the ladder.
The choice of deoxyribose rather than ribose in DNA provides a more stable structure that is less prone to breaking down. This stability is crucial for the long-term preservation of genetic information, allowing DNA to carry instructions for cellular function and heredity over generations.