The electron transfer in the respiratory chain involves NADH, a nucleotide deriv

Question

The electron transfer in the respiratory chain involves NADH, a nucleotide derivative, which is oxidized to NAD+ according to the following reaction: NADH + H+ +1 /2 O2 NAD+ + H2O This oxidation is highly exergonic. The standard free energy variation G of this reaction is -52.1 kcal / mol This reaction is coupled to the phosphorylation of ADP t allows the synthesis of 3 moles of ATP from ADP and phosphate per mole of oxidized NADH 3ADP + 3 Pi 3 ATP What is the efficiency of energy storage during these reactions? . How many ATP molecules could theoretically be formed per oxickzed NADH molecule? Standard-state free energy for ATP hydrolysis is 0"--30.5 kJ/mol

Explanation / Answer

NADH + H+ + ½ O2 ---> NAD+ + H2O

Go for this reaction is -52.1kcal/mol

1 kcal = 4.184 kJ.

Convert -52.1kcal/mol to kJ/mol by multiplying with 4.184

-52.1 x 4.184 = -218 kJ/mol

3ADP + 3Pi ---> 3 ATP

Standard state-free energy for ATP hydrolysis = -30.5 kJ/mol

Since one NADH generates 2.5 molecules of ATP with each molecule containing -30.5 kJ/mol of energy, the total amount of energy produced will be

2.5 mol *-30.5 kJ/mol = -76.25 kJ

The efficiency of energy storage during these reactions

= (Amount of energy in NADH generated into ATP / amount of energy within NADH) * 100

= (-76.25 kJ/ -218 kJ) * 100 = 34.98%

2.5 ATP molecules can theoretically be formed per oxidized NADH molecule.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.