The oxidation of NADH2 releases 2 electrons and 2 protons. This energy is then utilized to synthesize:
A) Two molecules of ATP.
B) One molecule of ATP.
C) Three molecules of ATP.
D) No ATP.
Answer (2)
The oxidation of NADH during cellular respiration releases energy used to create approximately three molecules of ATP through the electron transport chain and ATP synthase. Therefore, the correct answer is C) Three molecules of ATP.
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The question is about the process of oxidative phosphorylation in cellular respiration, specifically the role of NADH in ATP synthesis.
What is NADH?
NADH (Nicotinamide adenine dinucleotide) is a coenzyme found in all living cells. It is involved in redox reactions, carrying electrons from one reaction to another. NADH is the reduced form of NAD+, meaning it has accepted electrons and can act as an electron carrier.
How does NADH contribute to ATP synthesis?
In cellular respiration, particularly during oxidative phosphorylation, NADH is oxidized by the electron transport chain in the mitochondria. This process involves the transfer of electrons through a series of complexes (I to IV), which ultimately leads to the pumping of protons (H+) across the inner mitochondrial membrane, creating a proton gradient.
Role of oxidative phosphorylation:
As protons flow back through ATP synthase, driven by the proton gradient, ATP is synthesized from ADP and inorganic phosphate (Pi). This process of ATP production is called chemiosmosis.
ATP yield from NADH:
The oxidation of NADH results in the synthesis of approximately three molecules of ATP per molecule of NADH. Thus, for every NADH that donates electrons to the electron transport chain, about three molecules of ATP are generated.
Conclusion:
Given this understanding, the correct answer to the question is (c) Three molecules of ATP .
