Question

Which of the following is a nucleotide?

• A. Uridine
• B. Adenylic acid
• C. Guanine
• D. Guanosine

Answer 1

The Correct Option is B

To determine which of the given options is a nucleotide, let's first clarify what a nucleotide is. A nucleotide is a basic building block of nucleic acids, such as DNA and RNA. Each nucleotide consists of three components: a nitrogenous base, a phosphate group, and a five-carbon sugar (ribose or deoxyribose).

Let's analyze each of the given options:

1. Uridine: This is a nucleoside, which means it consists of a nitrogenous base (uracil) plus a sugar (ribose), but it lacks a phosphate group.
2. Adenylic acid: Also known as adenosine monophosphate (AMP). This compound consists of a nitrogenous base (adenine), a ribose sugar, and a single phosphate group. Therefore, it fits the definition of a nucleotide.
3. Guanine: This is a nitrogenous base alone, and by itself, it is neither a nucleoside nor a nucleotide.
4. Guanosine: This is a nucleoside, consisting of the nitrogenous base guanine and a ribose sugar, but without a phosphate group, so it is not a nucleotide.

Given these explanations, the correct answer is Adenylic acid, as it fulfills all the criteria of a nucleotide with a nitrogenous base, a sugar, and a phosphate group.