Final answer:
In glycolysis, glucose is phosphorylated to glucose-6-phosphate, by the enzyme hexokinase using a phosphate from ATP in an exergonic reaction, where the phosphoanhydride bond of ATP has higher energy than needed for forming a phosphoester bond.
Step-by-step explanation:
In the first step of glycolysis, glucose is phosphorylated to glucose-6-phosphate. This critical reaction is catalyzed by the enzyme hexokinase, which transfers a phosphate group from ATP to glucose, forming glucose-6-phosphate. The correct answer to this process is C) the phosphoanhydride bond of ATP has a higher energy of hydrolysis than is required for the formation of a phosphoester bond in glucose-6-phosphate. This phosphorylation reaction is exergonic (–ΔG), releasing energy.
The phosphorylated glucose molecule becomes more reactive, making it easier to undergo further reactions in the glycolytic pathway. Moreover, the addition of a negatively charged phosphate group ensures that the glucose-6-phosphate molecule cannot easily pass through the hydrophobic interior of the plasma membrane, thus, staying inside the cell. The released energy from the hydrolysis of ATP drives this reaction forward and is not reversible under cellular conditions, which disqualifies option B.
It is crucial to note that this process does require an enzyme (hexokinase), making option A incorrect. Also, the reaction is not endergonic; it does not require an input of energy to proceed, thus disqualifying option D.