Chapter 20, Problem 20.1VP

Interpretation Introduction

Interpretation: The basic functional groups in the given structures are to be identified.

Concept introduction: Deoxyribose nucleic acid is the basic functional unit of a cell. It consists of deoxyribose sugar, phosphate group and four nucleic bases. The nucleic acids are classified into purine and pyrimidine.

To determine: The basic functional groups in the given structures.

Answer to Problem 20.1VP

Solution

The functional group present in adenine is primary amine, in guanine is primary and secondary amine, in thymine is two secondary amine and in cytosine is primary and secondary amines along with carbonyl group.

Explanation of Solution

Explanation

Adenine is a $9$-member ring formed by fusion of six-member and five-membered ring. The functional group amine $\left({\text{NH}}_2\right)$ is attached to the six membered ring as shown in Figure 1.

Figure 1

The functional group present on guanine is amine $\left({\text{NH}}_2\right)$ group along with one carbonyl group $\left(\text{C}=\text{O}\right)$. The position of the functional group is shown in Figure 2.

Figure 2

Thymine consists of two secondary amine $\left({\text{R}}_2\text{NH}\right)$ groups and two carbonyl groups $\left(\text{C}=\text{O}\right)$. The position of the functional group is shown in Figure 3.

Figure 3

The functional groups attached to cytosine are one primary amine, two secondary amines, and one carbonyl group as shown in Figure 4.

Figure 4

Conclusion

The functional group present in adenine is primary amine, in guanine is primary and secondary amine, in thymine is two secondary amine and in cytosine is primary and secondary amines along with carbonyl group