Which three components make up a nucleotide?

• A. A phosphate group, a five-carbon sugar, and a nitrogenous base
• B. A phosphate group, a fatty acid, and a nitrogenous base
• C. A five-carbon sugar, a glycerol molecule, and a nitrogenous base
• D. A phosphate group, a five-carbon sugar, and an amino acid

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the structure of a nucleotide. A nucleotide is the building block of nucleic acids like DNA and RNA. It consists of three main components: a phosphate group, a five-carbon sugar, and a nitrogenous base.
2. Step 2: Analyze the options provided in the question. Compare each option to the known structure of a nucleotide to identify which components match the correct structure.
3. Step 3: Eliminate incorrect options. For example, a fatty acid and glycerol molecule are components of lipids, not nucleotides. Similarly, an amino acid is a building block of proteins, not nucleotides.
4. Step 4: Confirm the correct answer. The correct combination of components for a nucleotide is a phosphate group, a five-carbon sugar, and a nitrogenous base.
5. Step 5: Review the importance of each component. The phosphate group provides a negative charge, the five-carbon sugar (either ribose or deoxyribose) forms the backbone, and the nitrogenous base (adenine, thymine, cytosine, guanine, or uracil) carries genetic information.