GATE 2020 BM – Question 33
The source asks the energy from hydrolysis of one ATP molecule in kilocalories, to one decimal place. Give its conventional biochemical standard energy value.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 7.25 to 7.35
Explanation
The conventional standard free-energy release for ATP hydrolysis is approximately 7.3 kcal per mole, which is the numerical answer intended by the official key. It is not 7.3 kcal for one individual molecule: dividing by Avogadro’s number gives about 1.21×10⁻²³ kcal per molecule. The source omits the per-mole unit, so that distinction is explicit while its official 7.3 grading is retained.