Which of these equations demonstrates energetic coupling in a cell? Equation 1: ATP + H₂O $\rightarrow$ ADP + P_i
$\Delta$ G₁ = -7 kcal/mol
Equation 2: phosphoenolpyruvate + H₂O $\rightarrow$ pyruvate + P_i
$\Delta$ G₂ = -14.8 kcal/mol
Equation 3: glucose + P_i $\rightarrow$ glucose-6-phosphate + H₂O
$\Delta$ G₃ = +3.3 kcal/mol
Equation 4: ADP + P_i $\rightarrow$ ATP + H₂O
$\Delta$ G₃ = +7 kcal/mol

Question

Which of these equations demonstrates energetic coupling in a cell? Equation 1: ATP + H₂O

\rightarrow

ADP + P_i

\Delta

G₁ = -7 kcal/mol
Equation 2: phosphoenolpyruvate + H₂O

\rightarrow

pyruvate + P_i

\Delta

G₂ = -14.8 kcal/mol
Equation 3: glucose + P_i

\rightarrow

glucose-6-phosphate + H₂O

\Delta

G₃ = +3.3 kcal/mol
Equation 4: ADP + P_i

\rightarrow

ATP + H₂O

\Delta

G₃ = +7 kcal/mol

Quizplus · Accepted Answer

Energetic coupling in cells involves using the energy released from one reaction (exergonic) to drive another reaction that requires energy (endergonic). Equation 1 shows the hydrolysis of ATP to ADP, releasing energy (-7 kcal/mol), and Equation 3 shows the phosphorylation of glucose to glucose-6-phosphate, which requires energy (+3.3 kcal/mol). These two processes are often coupled in cells, with the energy from ATP hydrolysis driving the endergonic reaction of glucose phosphorylation.

Which of These Equations Demonstrates Energetic Coupling in a Cell →\rightarrow→

Which of These Equations Demonstrates Energetic Coupling in a Cell $\rightarrow$