Question

DNA is a polymer of nuclecotides which are linked too each other by $3^{\prime }-5^{\prime }$ phosphodiester bond.To prevent polymerization of nucleotide,which of the following modification would you choose?

• A. Replace purine with pyrimidine
• B. Remove/Replace $3^{\prime }$ OH group in deoxy ribose
• C. Remove /Replace $2^{\prime }$ Oh group with some other group in deoxy ribose
• D. Both $2$ and $3$

Answer 1

The correct option is B Remove/Replace $3^{\prime }$ OH group in deoxy ribose

Polymerization of nucleotide is done by forming phosphodiester bonds between OH groups of 3' carbon atom of one sugar and 5' carbon atom of another sugar of the nucleotide. The nucleotide base does not affect the formation of phosphodiester bonds so the first option is not right. The 2' OH does not have any part in the polymerization process, so option C and D cannot be right. By replacing or removing the OH group from 3' carbon atom the polymerization can be prevented.

So the correct option is 'Remove/replace 3' OH group in deoxy ribose'.