Deoxyribose

Definition

Deoxyribose is a five-carbon sugar molecule that is a crucial component of DNA, or deoxyribonucleic acid. This sugar differs from ribose, the sugar found in RNA, by the absence of one oxygen atom, which is what gives deoxyribose its name. It forms part of the backbone of DNA, linking to phosphate groups and nitrogenous bases to create the structure that encodes genetic information.

5 Must Know Facts For Your Next Test

1. Deoxyribose has the molecular formula C5H10O4 and is structurally a pentose sugar.
2. In DNA, deoxyribose is bonded to phosphate groups and nitrogenous bases, forming the nucleotides that make up the DNA strands.
3. The lack of one oxygen atom in deoxyribose compared to ribose makes DNA more chemically stable and less reactive.
4. Deoxyribose plays a critical role in the formation of the double helix structure of DNA by connecting with phosphate groups to create the sugar-phosphate backbone.
5. The sequence of nitrogenous bases attached to deoxyribose units in DNA encodes genetic information, determining traits and biological functions.

Review Questions

• How does deoxyribose contribute to the structure of DNA, and what are its main differences compared to ribose?
  • Deoxyribose contributes to the structure of DNA by forming part of the sugar-phosphate backbone that provides stability and supports the overall structure of the double helix. Unlike ribose found in RNA, deoxyribose lacks one oxygen atom at the 2' carbon position, which enhances its stability and reduces its reactivity. This difference is significant because it allows DNA to store genetic information more securely over long periods without being easily degraded.
• Discuss the importance of deoxyribose in nucleotide formation and how it affects DNA's stability compared to RNA.
  • Deoxyribose is essential for nucleotide formation in DNA as it combines with phosphate groups and nitrogenous bases to create nucleotides. The chemical structure of deoxyribose contributes to the overall stability of DNA; its absence of an oxygen atom at the 2' position means that it is less prone to hydrolysis compared to ribose in RNA. This increased stability is crucial for DNA's role in long-term information storage in cells.
• Evaluate how changes in deoxyribose structure could impact genetic coding and what implications this might have for biological processes.
  • If there were alterations in the structure of deoxyribose, such as adding an oxygen atom back into the molecule, it could lead to significant changes in how genetic coding functions. Such modifications might create a molecule similar to RNA, leading to increased reactivity and instability. This instability could affect the fidelity of genetic information transfer during replication and transcription processes, ultimately impacting protein synthesis and potentially leading to various diseases or developmental issues.

Related terms

Nucleotide: The basic building block of nucleic acids, consisting of a nitrogenous base, a sugar (deoxyribose in DNA), and a phosphate group.

DNA Backbone: The structural framework of DNA formed by alternating sugar (deoxyribose) and phosphate groups, providing stability and integrity to the DNA molecule.

Nitrogenous Base: The organic molecules attached to deoxyribose in DNA that pair together to form the rungs of the DNA ladder, including adenine, thymine, cytosine, and guanine.