Q. 17.16 - An Introduction to General, Organic, and Biological Chemistry

Question

What is the difference between the $3\text{'}$ end and the $5\text{'}$ end of a polynucleotide chain?

Step-by-Step Solution

Answer

One end of the polynucleotide chain contains a sugar with a free $5\text{'}$ phosphate group and the other end contains a free $3\text{'}$hydroxyl group ($OH$ group).

Step 1 : Introduction

The objective is to determine what is the difference between $3\text{'}$and $5\text{'}$ end of polynucleotide chain

Step 2 : Explanation

Nucleic acids are organic macromolecules that are present all over the cell. They were first discovered in the nuclei of cells. Nucleic acids, such as DNA and RNA, are found in all known forms of life. 

One of the components of nucleotide structure is nitrogen bases. Purines and pyrimidines are nitrogen bases that form various nucleotide structures.

Step 3 : Polynucleotide chain

The $3\text{'}$ end of the sugar unit is connected to the oxygen of the phosphate that is attached to the other nucleotide at its $5\text{'}$end in a polynucleotide chain. So one end of the polynucleotide chain contains a sugar with a free $5\text{'}$ phosphate group and the other end contains a free $3\text{'}$ hydroxyl group (data-custom-editor="chemistry" $\mathrm{OH}$ group).