Question

Inorganic phosphate is involved in which step of respiration?

• A. Glycolysis
• B. Krebs cycle
• C. Electron Transport System (ETS)
• D. Fermentation

Hint:

In glycolysis, inorganic phosphate (\( \mathrm{P_i} \)) is crucial for generating high-energy intermediates, particularly in the energy payoff phase.

Answer 1

The Correct Option is A

Inorganic phosphate (\( \mathrm{P_i} \)) is critical for glycolysis, especially in the conversion of glyceraldehyde-3-phosphate (G3P) to 1,3-bisphosphoglycerate. Glyceraldehyde-3-phosphate dehydrogenase catalyzes this reaction, where \(\mathrm{P_i}\) is added to G3P. This process is vital for generating high-energy intermediates that ultimately yield ATP. While inorganic phosphate indirectly contributes to the Krebs cycle and ETS, its direct addition to metabolic intermediates is exclusive to glycolysis.