Chapter 24, Problem 105A

Interpretation Introduction

Interpretation: The structural difference between DNA and RNA needs to be interpreted.

Concept introduction: An unbranched polymer that is made up of nucleotides (monomeric units) is known as nucleic acid. The nucleotide is a combination of sugar, phosphate, and base.

The nucleic acids are categorized into two types that are as follows:

• Deoxyribonucleic acid shortened as DNA
• Ribonucleic acid shortened as RNA

Answer to Problem 105A

The structural differences in DNA and RNA lie in the bases that are present. A DNA consists of bases i.e., guanine, adenine, cytosine, and thymine while in RNA the thymine base is replaced by uracil while the remaining bases stay the same.

Explanation of Solution

DNA is the building block of organisms that is made up of nucleotides and it is a double-stranded molecule. The nucleotide is a combination of sugar, phosphate, and base. The DNA molecule is made up of a phosphate group, and a sugar unit which is known as deoxyribose.

The bases that are present in DNA molecules are guanine, adenine, cytosine, and thymine which are shortened as G, A, C, and T respectively. The pairing of bases is done in a way that A is always paired with T, while G is paired with C.

The structure of DNA is represented below:

  

RNA stands for ribonucleic acid, which is a single-stranded molecule. The backbone of the RNA molecule is made up of a phosphate group and a sugar unit which is known as ribose. The bases that are present in RNA molecules are adenine, uracil, guanine, and cytosine which are shortened as A, U, G, and C respectively.

The structure of RNA is represented below:

  

Conclusion

The structural differences in DNA and RNA lie in the bases that are present. A DNA consists of bases i.e., guanine, adenine, cytosine, and thymine while in RNA the thymine base is replaced by uracil while the remaining bases stay the same.