Chapter 17, Problem 17.26UKC

Label each statement as pertaining to DNA, RNA, or both.

1. a. The polynucleotide is single stranded.
2. b. The polynucleotide may contain guanine.
3. c. The polynucleotide may contain UMP.
4. d. The polynucleotide is a polymer of deoxyribonucleotides.

Interpretation Introduction

Interpretation:

Whether the statement that polynucleotide is single stranded labeled as DNA, RNA or both has to be determined.

Concept Introduction:

Nucleotide is defined as basic unit for formation of nucleic acid that is essential for completion of metabolic reactions in body. The three basic components of nucleotide are as follows:

1. Nitrogen-containing base

2. Pentose sugar

3. Phosphate group

Nucleic acids are defined as polymers of nucleotides. There are two types of nucleic acids as follows:

(a) DNA

(b) RNA

The table below shows the differences between DNA and RNA as follows:

$\begin{array}{cc}\text{DNA}\left(\text{deoxyribonucleic acid}\right)& \text{RNA}\left(\text{ribonucleic acid}\right)\\ \begin{array}{c}\text{The monosaccharide unit in}\\ \text{DNA is deoxyribose sugar that does not}\\ \text{have OH group at C}{\text{2}}^{\prime }\text{.}\end{array}& \begin{array}{l}\text{The monosaccharide unit in}\\ \text{ RNA }\text{}\text{is pentose sugar with}\\ \text{OH group at C}{\text{2}}^{\prime }\text{.}\end{array}\\ \begin{array}{c}\text{It contains bases like adenine,guanine,}\\ \text{cytosine and thymine}\text{.}\end{array}& \begin{array}{c}\text{It contains bases like adenine, guanine,}\\ \text{cytosine and uracil}\text{.}\end{array}\\ \text{It forms double helix strand}\text{.}& \text{It is single stranded}\text{.}\\ \begin{array}{c}\text{It stores genetic information}\\ \text{in organism}\text{.}\end{array}& \begin{array}{c}\text{It transmits the information for the}\\ \text{synthesis of proteins in cells}\text{.}\end{array}\end{array}$

Answer to Problem 17.26UKC

The statement polynucleotide is single stranded is labeled as RNA.

Explanation of Solution

RNA molecule contains one strand that is composed of ribonucleotides. Therefore, the statement polynucleotide is single-stranded is labeled as RNA.

Interpretation Introduction

Interpretation:

Whether the statement that polynucleotide may contain guanine labeled as DNA, RNA or both has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 17.26UKC

The statement polynucleotide may contain guanine is labeled as both that is DNA and RNA.

Explanation of Solution

DNA and RNA consist of four bases each. Both have three similar bases that are adenine, cytosine and guanine but differ in thymine in DNA and uracil in RNA. Since polynucleotide contains guanine, therefore, it can be both that is either DNA or RNA. Hence, the statement polynucleotide may contain guanine is labeled as both that is DNA and RNA.

Interpretation Introduction

Interpretation:

Whether the statement that polynucleotide may contain UMP labeled as DNA, RNA or both has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 17.26UKC

The statement polynucleotide may contain UMP is labeled as RNA.

Explanation of Solution

Three letter abbreviation, UMP states that it has ribose sugar. In the given abbreviation, U stands for uracil base, M stands for mono and P stands for phosphate group. Thus no prefix is used like “deoxy” for DNA. Therefore, the statement polynucleotide may contain UMP is labeled as RNA.

Interpretation Introduction

Interpretation:

Whether the statement that polynucleotide is a polymer of deoxyribonucleotides labeled as DNA, RNA or both has to be determined.

Concept Introduction:

Refer to part (a).

Answer to Problem 17.26UKC

The statement polynucleotide is a polymer of deoxyribonucleotides is labeled as DNA.

Explanation of Solution

Polynucleotide is a polymer that is composed of more than one nucleotide unit that is bonded to each other through a covalent bond. Polynucleotide is of DNA or RNA nucleotides. If it is formed of deoxyribose sugar then it is a polymer of deoxyribonucleotides and thus is a part of DNA. Hence, the statement polynucleotide is a polymer of ribonucleotides is labeled as DNA.