Which statement best describes the components of nucleic acids?
The Correct Answer and Explanation is :
Correct answer:
Nucleic acids are composed of nucleotides, which are made up of three components: a nitrogenous base, a five-carbon sugar (either ribose or deoxyribose), and one or more phosphate groups.
Explanation:
Nucleic acids, such as DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are essential biomolecules that carry genetic information and play a crucial role in various biological processes. The building blocks of nucleic acids are nucleotides, and each nucleotide consists of three key components:
- Nitrogenous Base:
This component is responsible for the coding properties of DNA and RNA. There are two categories of nitrogenous bases: purines and pyrimidines. Purines include adenine (A) and guanine (G), while pyrimidines include cytosine (C), thymine (T), and uracil (U). In DNA, thymine is used, but in RNA, uracil takes its place. - Five-Carbon Sugar:
The sugar in nucleotides differs between DNA and RNA. DNA contains deoxyribose, while RNA contains ribose. The difference lies in the presence or absence of an oxygen atom; deoxyribose lacks one oxygen atom on the second carbon of the sugar ring, hence the prefix “deoxy-.” - Phosphate Group(s):
Nucleotides contain one or more phosphate groups attached to the sugar molecule. These phosphates form the backbone of the nucleic acid by linking the sugar of one nucleotide to the sugar of another through phosphodiester bonds. This creates a repeating sugar-phosphate chain, which is integral to the structure of both DNA and RNA.
The specific sequence of nitrogenous bases along the nucleic acid chain encodes genetic information, which is essential for processes like protein synthesis, cellular replication, and hereditary transmission. Nucleic acids’ structure allows them to store and transfer vast amounts of biological information in a stable and precise manner.