(Solved): The reaction above shows the conversion of phosphoenolpyruvate (the reactant) into pyruvate (the p ...

The reaction above shows the conversion of phosphoenolpyruvate (the reactant) into pyruvate (the product) by the enzyme pyruvate kinase, the final step of glycolysis in the human body. Like many biochemical reaction equations shown in textbooks, not all atoms are explicitly shown in the reactants and products. The curved arrow attached to the reaction arrow indicates that one molecule of ADP is converted to ATP during this reaction, and one $$\mathrm{H}+$$ ion is also consumed. Identify all redox transformations between the phosphoenolpyruvate and pyruvate. A. None of the labeled carbon atoms undergo oxidation or reduction because each has a full octet and no lone pairs in both structures. The $${\mathrm{H}}^{+}$$ion that is above the reaction arrow ends up bonded to carbon 3 . It is reduced from +1 to 0 . Because there is reduction happening to the $${\mathrm{H}}^{+}$$, there must also be some oxidation occurring in the transformation from ADP to ATP. B. The carbon labeled 1 has an oxidation state of +3 in both the phosphoenolpyruvate and pyruvate molecules, so it does not undergo any redox changes. The carbon labeled 2 has an oxidation state of +1 in phosphoenolpyruvate and +2 in the pyruvate molecule, so it undergoes oxidation. The carbon labeled 3 has an oxidation state of -2 in the phosphoenolpyruvate molecule, and -3 in pyruvate, so it undergoes reduction. The $$\mathrm{H}+$$ ion that is above the reaction arrow ends up bonded to carbon 3 . It is reduced from +1 to 0 . Because there are two electrons of reduction happening and just one electron of oxidation, there must also be some oxidation occurring in the transformation from ADP to ATP. C. The carbon labeled 1 has an oxidation state of +3 in both the phosphoenolpyruvate and pyruvate molecules, so it does not undergo any redox changes. The carbon labeled 2 has an oxidation state of -1 in phosphoenolpyruvate and -2 in the pyruvate molecule, so it undergoes reduction. The carbon labeled 3 has an oxidation state of +2 in the phosphoenolpyruvate molecule, and +3 in pyruvate, so it undergoes reduction. The $$\mathrm{H}+$$ ion that is above the reaction arrow ends up bonded to carbon 3 . It is reduced from +1 to 0 . Because there are two electrons of reduction happening and just one electron of oxidation, there must also be some oxidation occurring in the transformation from ADP to ATP. D. The carbon labeled 1 has an oxidation state of +3 in both the phosphoenolpyruvate and pyruvate molecules, so it does not undergo any redox changes. The carbon labeled 2 has an oxidation state of +1 in phosphoenolpyruvate and +2 in the pyruvate molecule, so it undergoes oxidation. The carbon labeled 3 has an oxidation state of -2 in the phosphoenolpyruvate molecule, and -3 in pyruvate, so it undergoes reduction. Because both carbons undergoing oxidation state changes are changed by one electron, it is possible that no other redox changes are happening. E. The carbon labeled 1 has an oxidation state of +3 in both the phosphoenolpyruvate and pyruvate molecules, so it does not undergo any redox changes. The carbon labeled 2 has an oxidation state of -1 in phosphoenolpyruvate and -2 in the pyruvate molecule, so it undergoes oxidation. The carbon labeled 3 has an oxidation state of +2 in the phosphoenolpyruvate molecule, and +3 in pyruvate, so it undergoes reduction. Because both carbons undergoing oxidation state changes are changed by one electron, it is possible that no other redox changes