Comprehension
Ribose and 2-deoxyribose have an important role in biology. Among the most important derivatives are those with phosphate groups attached at the 5 position. Mono-, di- and tri-phosphate forms are important, as well as 3-5 cyclic monophosphates. Purines and pyrimidines form an important class of compounds with ribose and deoxyribose. When these purine and pyrimidine derivatives are coupled to a ribose sugar, they are called nucleosides.
Question: 1

What products would be formed when DNA is hydrolyzed? How is DNA different from RNA with reference to structure?

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Remember, DNA stores genetic information and is double-stranded, while RNA is involved in protein synthesis and is single-stranded.
Updated On: Jan 14, 2026
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Solution and Explanation

When DNA undergoes hydrolysis, nucleotides are produced. This process cleaves the phosphodiester bonds linking nucleotides, yielding separate nucleotide molecules. DNA distinguishes itself from RNA by its sugar component; DNA utilizes deoxyribose, whereas RNA uses ribose. Furthermore, DNA exists as a double-stranded molecule forming a double helix, while RNA is single-stranded. The nitrogenous bases also differ: DNA employs thymine, and RNA uses uracil instead of thymine.
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Question: 2

Differentiate between nucleotide and nucleoside.

Updated On: Jan 14, 2026
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Solution and Explanation

A nucleoside comprises a nitrogenous base (purine or pyrimidine) and a sugar (ribose or deoxyribose), but it does not contain a phosphate group. In contrast, a nucleotide is a nucleoside with one or more phosphate groups bonded to the sugar molecule. The addition of a phosphate group designates the nucleotide as a fundamental unit of nucleic acids.
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Question: 3

Mention two important functions of nucleic acids.

Updated On: Jan 14, 2026
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Solution and Explanation

Nucleic acids serve two crucial functions: 1. Storing and transmitting genetic data via DNA. 2. Facilitating protein synthesis through RNA, which acts as a messenger between DNA and ribosomes.
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Question: 4

Name the linkage which joins two nucleotides. Name the base that is found in nucleotide of RNA but not DNA.

Updated On: Jan 14, 2026
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Solution and Explanation

The phosphodiester bond links two nucleotides by connecting the 3’ carbon of one sugar to the 5’ carbon of the next. Uracil (U) is present in RNA, replacing thymine (T).
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