How is the production of ATP in the electron transport chain similar to the production of ATP during the light dependent reactions of photosynthesis?
The correct answer and explanation is :
Answer:
The production of ATP in the electron transport chain (ETC) of cellular respiration is similar to ATP production during the light-dependent reactions of photosynthesis because both processes use a proton gradient (chemiosmosis) and ATP synthase to generate ATP.
Explanation:
Both processes involve the movement of electrons through a chain of proteins embedded in a membrane, leading to the generation of ATP through oxidative phosphorylation in cellular respiration and photophosphorylation in photosynthesis.
- Electron Transport & Proton Gradient Formation
- In cellular respiration, the ETC is located in the inner mitochondrial membrane. High-energy electrons from NADH and FADH₂ pass through protein complexes, pumping H⁺ ions into the intermembrane space, creating an electrochemical gradient.
- In photosynthesis, the light-dependent reactions occur in the thylakoid membrane. Light excites electrons in photosystem II, which travel through the ETC, pumping H⁺ ions into the thylakoid lumen, creating a similar gradient.
- ATP Synthase & Chemiosmosis
- In both processes, H⁺ ions diffuse back through ATP synthase, an enzyme that uses the flow of protons to convert ADP + Pi into ATP.
- In cellular respiration, this process is called oxidative phosphorylation because oxygen serves as the final electron acceptor.
- In photosynthesis, it is called photophosphorylation because light energy drives electron movement.
- Energy Source Difference
- Cellular respiration relies on the energy from glucose oxidation.
- Photosynthesis uses light energy to excite electrons and drive ATP production.
Thus, both systems use electron transport chains, proton gradients, and ATP synthase, but they differ in energy sources and final electron acceptors (oxygen in respiration, NADP⁺ in photosynthesis).