---
title: "A student investigates the biochemical synthesis of glucose-6-phosphate from glucose and inorganic phosphate (\\(\\text{P}_i\\)). The individual chemical equations and their standard Gibbs free energy changes at \\(298\\text{ K}\\) are shown below.  \\[ \\text{Glucose(aq)} + \\text{P}_i\\text{(aq)} \\rightleftharpoons \\text{Glucose-6-phosphate(aq)} + \\text{H}_2\\text{O(l)} \\quad \\Delta G^\\circ_{298} = +14\\text{ kJ/mol}_{\\text{rxn}} \\] \\[ \\text{ATP(aq)} + \\text{H}_2\\text{O(l)} \\rightleftharpoons \\text{ADP(aq)} + \\text{P}_i\\text{(aq)} \\quad \\Delta G^\\circ_{298} = -31\\text{ kJ/mol}_{\\text{rxn}} \\]  Which of the following statements best explains whether the net reaction coupling the phosphorylation of glucose to the hydrolysis of \\(\\text{ATP}\\) is thermodynamically favorable under standard conditions at \\(298\\text{ K}\\)?"
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url: "https://nerd-notes.com/ubq/121396/"
date_modified: "2026-08-23T05:02:04+00:00"
---

# A student investigates the biochemical synthesis of glucose-6-phosphate from glucose and inorganic phosphate (\(\text{P}_i\)). The individual chemical equations and their standard Gibbs free energy changes at \(298\text{ K}\) are shown below.

\[ \text{Glucose(aq)} + \text{P}_i\text{(aq)} \rightleftharpoons \text{Glucose-6-phosphate(aq)} + \text{H}_2\text{O(l)} \quad \Delta G^\circ_{298} = +14\text{ kJ/mol}_{\text{rxn}} \]
\[ \text{ATP(aq)} + \text{H}_2\text{O(l)} \rightleftharpoons \text{ADP(aq)} + \text{P}_i\text{(aq)} \quad \Delta G^\circ_{298} = -31\text{ kJ/mol}_{\text{rxn}} \]

Which of the following statements best explains whether the net reaction coupling the phosphorylation of glucose to the hydrolysis of \(\text{ATP}\) is thermodynamically favorable under standard conditions at \(298\text{ K}\)?

A student investigates the biochemical synthesis of glucose-6-phosphate from glucose and inorganic phosphate (\(\text{P}_i\)). The individual chemical equations and their standard Gibbs free energy changes at \(298\text{ K}\) are shown below.

\[ \text{Glucose(aq)} + \text{P}_i\text{(aq)} \rightleftharpoons \text{Glucose-6-phosphate(aq)} + \text{H}_2\text{O(l)} \quad \Delta G^\circ_{298} = +14\text{ kJ/mol}_{\text{rxn}} \]
\[ \text{ATP(aq)} + \text{H}_2\text{O(l)} \rightleftharpoons \text{ADP(aq)} + \text{P}_i\text{(aq)} \quad \Delta G^\circ_{298} = -31\text{ kJ/mol}_{\text{rxn}} \]

Which of the following statements best explains whether the net reaction coupling the phosphorylation of glucose to the hydrolysis of \(\text{ATP}\) is thermodynamically favorable under standard conditions at \(298\text{ K}\)?

- **A.** The coupled reaction is thermodynamically favorable because \(\text{ATP}\) acts as a catalyst that lowers the activation energy of the phosphorylation step, accelerating the rate of product formation.
- **B.** The coupled reaction is thermodynamically favorable because the overall standard Gibbs free energy change is negative (\(\Delta G^\circ_{298} = -17\text{ kJ/mol}_{\text{rxn}}\)), resulting in an equilibrium constant \(K > 1\).
- **C.** The coupled reaction is thermodynamically unfavorable because the synthesis step requires an input of free energy (\(\Delta G^\circ_{298} = +14\text{ kJ/mol}_{\text{rxn}}\)), preventing the net conversion of glucose to product.
- **D.** The coupled reaction is thermodynamically unfavorable because the hydrolysis of \(\text{ATP}\) produces two product species from one reactant, decreasing the total entropy of the system.

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/121396/*