Ribose sugar

Definition

Ribose sugar is a five-carbon sugar molecule that plays a crucial role in the structure of RNA (ribonucleic acid). This sugar forms the backbone of RNA, connecting with phosphate groups and nitrogenous bases, which together contribute to the formation of RNA's structure and function. Ribose is essential for cellular processes such as protein synthesis and gene expression, as it is involved in the assembly of RNA nucleotides.

5 Must Know Facts For Your Next Test

1. Ribose has the chemical formula C5H10O5 and is classified as an aldopentose due to its five carbon atoms and aldehyde group.
2. In RNA, ribose sugars are connected by phosphodiester bonds, linking the 5' carbon of one ribose to the 3' carbon of another, forming a sugar-phosphate backbone.
3. The presence of the hydroxyl (-OH) group on the 2' carbon of ribose makes RNA more reactive and less stable than DNA, which contains deoxyribose.
4. Ribose is also involved in the formation of ATP (adenosine triphosphate), a crucial energy carrier in cells, highlighting its importance in metabolism.
5. Ribose can be synthesized in cells through the pentose phosphate pathway or obtained from dietary sources, underscoring its role in cellular energy production.

Review Questions

• How does ribose sugar contribute to the structure and function of RNA?
  • Ribose sugar is integral to the structure of RNA because it forms part of the nucleotide building blocks. Each ribose connects to a phosphate group and a nitrogenous base, creating the backbone of RNA strands. This configuration not only provides structural stability but also enables RNA to carry genetic information and play roles in protein synthesis and gene regulation.
• Compare and contrast ribose with deoxyribose in terms of structure and function within nucleic acids.
  • Ribose and deoxyribose are both five-carbon sugars but differ significantly in their structure. Ribose has a hydroxyl (-OH) group on the 2' carbon, while deoxyribose lacks this oxygen atom, making it more stable. This difference influences the stability and reactivity of RNA versus DNA; RNA is more reactive due to ribose's structure, while DNA’s stability allows it to store genetic information securely over long periods.
• Evaluate the significance of ribose sugar in cellular metabolism and energy production.
  • Ribose sugar plays a vital role in cellular metabolism by being part of ATP, which is the primary energy currency in cells. It also contributes to other important molecules like NADH and FADH2, which are essential for cellular respiration. By facilitating energy transfer within cells, ribose ensures that metabolic processes run smoothly, highlighting its fundamental importance beyond just being a structural component of RNA.

Related terms

RNA: Ribonucleic acid, a nucleic acid present in all living cells that plays roles in coding, decoding, regulation, and expression of genes.

Deoxyribose: A five-carbon sugar similar to ribose, but lacking one oxygen atom; it is a key component of DNA (deoxyribonucleic acid).

Nucleotide: The basic building block of nucleic acids, composed of a ribose sugar, a phosphate group, and a nitrogenous base.