Question

Which one of the following organic compounds is composed of only (i) a nitrogen containing base, (ii) a single five-carbon sugar, and (iii) a triphosphate?

• A. Nucleoside
• B. Nucleotide
• C. Base
• D. Nucleic acid

Hint:

Nucleotides are the building blocks of nucleic acids, consisting of a nitrogenous base, a five-carbon sugar, and a phosphate group.

Answer 1

The Correct Option is B

Step 1: Understanding the components.
A nucleotide is composed of three components: a nitrogenous base, a five-carbon sugar (ribose or deoxyribose), and a phosphate group (which can be a mono-, di-, or triphosphate).

Step 2: Analyzing the options.
- (A) Incorrect, a nucleoside consists of a nitrogenous base and a five-carbon sugar but does not include a phosphate group.
- (B) Correct, a nucleotide is composed of a nitrogenous base, a five-carbon sugar, and a triphosphate.
- (C) Incorrect, a base refers only to the nitrogen-containing molecule and does not include sugar or phosphate groups.
- (D) Incorrect, nucleic acids are large molecules made of long chains of nucleotides, but they are not a single organic compound as described in the question.

Step 3: Conclusion.
The correct answer is (B) Nucleotide.