Certain nucleic acids harbor significant free energy that can be released and coupled to the synthesis of biological molecules. Which of the following represents a nucleic acid form containing the greatest amount of free energy?

Question

Quizplus · Accepted Answer

Adenosine triphosphate (ATP) contains three phosphate groups, and the bonds between these phosphates (particularly the terminal phosphate bond) store a significant amount of free energy. When ATP is hydrolyzed to ADP or AMP, this energy is released and can be used to drive various biological processes.  The high free energy in nucleic acids is imparted by the formation of phosphate bonds. The nucleobase and nucleosides do not contain sufficient energy to drive biosynthetic processes. The phosphate in a monophosphate nucleotide is linked via an ester bond to the ribose. The di- and tri-phosphates of nucleotides are linked by anhydride bonds. Acid anhydride bonds have a high ΔG0′ for hydrolysis imparting upon them a high potential to transfer the phosphates to other molecules. Since the triphosphate nucleotide contains 2 phosphoanhydride bonds, it is this form that has the greatest level of free energy.

Certain Nucleic Acids Harbor Significant Free Energy That Can Be