Water Splitting & Proton Accumulation — NEET Biology
✅ Asked in NEET 2022Since splitting of the water molecule takes place on the inner side of the membrane, the protons or hydrogen ions that are produced by the splitting of water accumulate within the lumen of the thylakoids.
During light reactions in photosynthesis, water molecules split inside the thylakoid lumen (not outside), releasing protons (H⁺ ions) and oxygen. These protons accumulate specifically in the thylakoid lumen, creating a proton gradient across the thylakoid membrane. Many students mistakenly think water splitting happens in the stroma or that protons are equally distributed everywhere. The critical point to remember: the location of water splitting (inner membrane side) directly causes proton concentration inside the thylakoid lumen, which drives ATP synthesis. NTA tests this because understanding compartmentalization and ion gradients is fundamental to photosynthesis mechanisms.
Identify the correct statements regarding chemiosmotic hypothesis: (NEET 2022 Phase 2) (a) Splitting of the water molecule takes place on the inner side of the membrane. (b) Protons accumulate within the lumen of the thylakoids. (c) Primary acceptor of electron transfers the electrons to an electron carrier. (d) NADP reductase enzyme is located on the stroma side of the membrane. (e) Protons increase in number in stroma.
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