Which of the following would allow an energetically unfavorable process to occur in the cell?

• A. Increasing the concentration of reactants
• B. Increasing the concentration of products
• C. Coupling with ATP hydrolysis
• D. Decreasing the temperature

Answer: (C)

Verified step by step guidance

1. Understand the concept of an energetically unfavorable process: In chemistry, an energetically unfavorable process is one that requires energy input to proceed. This is often because the process has a positive Gibbs free energy change (ΔG > 0).
2. Learn about ATP hydrolysis: ATP (adenosine triphosphate) is a molecule that stores energy in its phosphate bonds. Hydrolysis of ATP involves breaking these bonds, releasing energy that can be used to drive other processes. The reaction is: ${\mathrm{ATP}}_4(aq)+H_{2}O(l)\to {\mathrm{ADP}}_3(aq)+P_{\mathrm{i}}(aq)+H+(aq)$
3. Explore the concept of coupling reactions: In cellular processes, energetically unfavorable reactions can be coupled with energetically favorable ones, such as ATP hydrolysis, to make the overall process favorable. This is because the energy released from ATP hydrolysis can be used to drive the unfavorable reaction forward.
4. Consider the effect of reactant and product concentrations: Increasing the concentration of reactants can shift the equilibrium position of a reaction according to Le Chatelier's principle, potentially making a reaction more favorable. However, this does not change the inherent energy requirement of the process.
5. Evaluate the impact of temperature: Decreasing the temperature generally slows down reaction rates and can affect the equilibrium position, but it does not inherently make an energetically unfavorable process favorable. Temperature changes affect the kinetics rather than the thermodynamics of a reaction.