Which substances are the three parts of an RNA nucleotide? phosphate, ribose, and uracil phosphate, deoxyribose, and uracil phosphate, deoxyribose, and adenine phosphate, ribose, and thymine
The Correct Answer and Explanation is:
The correct answer is phosphate, ribose, and uracil.
An RNA nucleotide is made up of three key components:
- Phosphate group: This part of the nucleotide is responsible for linking the nucleotides together via phosphodiester bonds, forming the backbone of the RNA strand.
- Ribose sugar: RNA contains the sugar ribose, which is a five-carbon sugar. The ribose is distinguished from deoxyribose (found in DNA) by the presence of a hydroxyl group (-OH) attached to the 2′ carbon atom of the sugar. This hydroxyl group makes RNA more reactive and less stable than DNA.
- Nitrogenous base: There are four possible nitrogenous bases in RNA: adenine (A), cytosine (C), guanine (G), and uracil (U). Uracil is unique to RNA, replacing thymine (T), which is found in DNA. Uracil pairs with adenine during the formation of RNA strands.
The main difference between RNA and DNA is in the sugar. RNA contains ribose, whereas DNA contains deoxyribose. The deoxyribose sugar in DNA lacks the hydroxyl group at the 2′ position, making DNA more stable and less reactive.
When constructing a nucleic acid, the nitrogenous bases pair as follows in RNA: adenine (A) pairs with uracil (U), while guanine (G) pairs with cytosine (C). In DNA, adenine pairs with thymine (T) and guanine pairs with cytosine. This difference in base pairing is important for maintaining the structure and function of the respective nucleic acids.
In summary, the correct components for an RNA nucleotide are a phosphate group, a ribose sugar, and a nitrogenous base (such as uracil). This structure allows RNA to function in protein synthesis, gene expression, and various other cellular processes.
