Which specific sugar is found in RNA ribonucleic acid molecules as part of their nucleotide structure?

Introduction / Context:
DNA and RNA are both nucleic acids, but they differ in several key structural features. One important difference is the type of pentose sugar present in their nucleotides. This question asks you to recall which sugar is part of RNA, testing your understanding of basic molecular biology and the distinction between DNA and RNA.

Given Data / Assumptions:

• The question focuses on RNA ribonucleic acid.

• It asks specifically for the sugar found in RNA nucleotides.

• Several common sugars are listed, including deoxyribose and ribose.

• Only one of the sugars listed is correct for RNA.

Concept / Approach:
The name ribonucleic acid itself hints at the sugar present, as the word ribo refers to ribose. RNA nucleotides contain the pentose sugar ribose, whereas DNA deoxyribonucleic acid contains deoxyribose, which lacks one oxygen atom compared to ribose. Glucose, sucrose, and fructose are common carbohydrates associated with energy storage and transport in cells, but not specifically with nucleic acid backbones. Therefore, by remembering the naming convention and structural differences, we can choose the correct sugar for RNA.

Step-by-Step Solution:
Step 1: Note that the full form of RNA is ribonucleic acid. Step 2: Recognize that the prefix ribo refers to the sugar ribose in the nucleotide. Step 3: Recall that DNA uses deoxyribose, a related sugar that has one less oxygen atom at the second carbon position. Step 4: Understand that glucose, sucrose, and fructose are not the sugars that form the backbone of nucleic acids. Step 5: Conclude from this that ribose is the sugar present in RNA nucleotides.

Verification / Alternative check:
Textbooks often display side by side diagrams comparing the structures of DNA and RNA. In these figures, DNA is labeled deoxyribonucleic acid and RNA is labeled ribonucleic acid, with captions that point out deoxyribose versus ribose sugars in the backbone. These diagrams clearly show ribose in RNA and deoxyribose in DNA, providing a quick verification of the correct sugar for RNA.

Why Other Options Are Wrong:

Deoxyribose: This sugar is part of DNA, not RNA. DNA nucleotides contain deoxyribose in their backbone.

Glucose: A simple sugar used mainly for energy, not the structural sugar of nucleic acids.

Sucrose: A disaccharide composed of glucose and fructose, used in plants for transport, not as a nucleic acid sugar.

Fructose: Another simple sugar found in fruits and honey, not used as the backbone sugar in RNA.

Common Pitfalls:
A typical confusion is mixing up ribose and deoxyribose, especially because their names sound similar. Some learners also forget the meaning of the term ribo in RNA. To avoid this, remember that the extra letter deoxy in DNA indicates a missing oxygen, while RNA retains the original ribose. Associating RNA with ribose and DNA with deoxyribose helps keep the two sugars clearly separated in memory.

Final Answer:
The sugar found in RNA is Ribose.