Question

Adenylic acid is
A. Nitrogen base
B. Nucleoside
C. Nucleotide
D. Amino acid

Answer 1

Hint: When only nitrogenous base is present along with the sugar group it is called as nucleoside and when all the three basic components like nitrogenous base, sugar group and phosphate group are present, they are together known as nucleotide.

Complete answer:
The correct answer is (C).
The basic components of the genetic material like DNA or RNA are the nucleic acids.
Structurally, nucleotide can be defined as the combination of a base and sugar and phosphate group and also another form which can be simply written as nucleoside is nitrogenous base (any of the five) + pentose sugar (either deoxyribose in case of DNA or ribose sugar in case of RNA).
The purine adenine which is a nine carbon member has doubled ringed nitrogenous base and when the ribose sugar is added to it, it forms the nucleoside which is known as adenosine. When phosphoric acid is added to this nucleoside adenosine, it gets converted into adenylic acid which is thus a nucleotide.
There are in total five nitrogenous bases- adenine, guanine, cytosine, thymine and uracil. Out of the five, adenine and guanine are the purines and they are found in both DNA and RNA. Rest of the three are together called as pyrimidines, thymine and cytosine are present in the DNA whereas the pyrimidine thymine gets replaced by another pyrimidine called as uracil in case of RNA.
In the genetic material, sugar and phosphate groups are known to form the backbone whereas the nitrogenous bases are stacked parallel to each other perpendicularly on the strands of the DNA.

Note: Adenylic acid is composed of three subunits, one of them is nitrogenous base adenine, other is ribose sugar group and third one is phosphoric acid, a phosphate group and hence called as nucleotide. The amino acids can never be related to any nucleotide or nucleoside as they are monomers of proteins or long polypeptide chains.