Question

The reaction to form a phosphate–ester linkage between two nucleotides can be approximated as follows:

Would you predict the formation of a dinucleotide from two nucleotides to be a spontaneous process?

Short answer

Formation of a dinucleotide from two nucleotides is a non-spontaneous process.

Step-by-step solution

To predict the formation 

To be able to predict the spontaneity of the formation of the dinucleotide, first we must consider its values for the free energy equation. It is given by the equation

ΔG=ΔH−TΔS.

Observing the reaction of the two nucleotides, to be able to form the dinucleotide, it is necessary to break the P-O and O-H bonds to form new P-O and O-H bonds. This means that the value for ΔH is approximately 0 since bonds formed are equal to bonds broken.

Determine spontaneity

The value of ΔS would be negative due to the positional probability decreasing since the nucleotides form one dinucleotide or molecule.

Considering these values, we can say that ΔG>0 hence, the reaction requires energy to proceed, and so it is non-spontaneous and unfavourable.

Hence formation of a dinucleotide from two nucleotides is a non-spontaneous process.