Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

What type of sugar is found in RNA?

1. Glucose

2. Fructose

3. Ribose

4. Deoxyribose

The correct answer is: Ribose

The type of sugar found in RNA is ribose. Ribose is a five-carbon sugar (pentose) that plays a critical role in the structure of RNA molecules. In RNA, ribose serves as the backbone, linking the nitrogenous bases (adenine, cytosine, guanine, and uracil) to phosphate groups. This structure is vital because it allows RNA to perform its functions in the cell, including encoding genetic information and facilitating protein synthesis. Other sugars mentioned, like glucose and fructose, are not components of RNA. Glucose is a six-carbon sugar that primarily serves as an energy source in cells, while fructose is a fruit sugar that also provides energy but is not part of RNA structure. Deoxyribose, a similar sugar, is found in DNA, but it lacks one oxygen atom compared to ribose, distinguishing the two nucleic acids from one another. Understanding the specific role of ribose in RNA helps clarify the differences between RNA and DNA as well as their respective functions in biological systems.