本题目来源于试卷: Interaction & Interdependence C.3 Photosynthesis，类别为 IB生物学
[单选题]
What is the main source of hydrogen kwh/q;m).wqtvx vj ismg 7 +88ions in the lk tgy0 6 ;(.gufz(fmukuk6,osight-dependent reactions for phot .tugzko60ms( uf(y;kfugk6 ,osynthesis?
A. $H_2O$
B. $ATP$
C. $C_6HO_6$
D. $NADPH$
参考答案: A
本题详细解析:
A In the light-dependent reactions for photosynthesis, hydrogen ions, also known as the protons, are important in creating a proton gradient. The main source of the hydrogen ions in the light-dependent reactions is water,$H_2O$. Photolysis of water results in the release of electrons, hydrogen ions and oxygen. ATP (Choice B) is not a source of hydrogen ions. ATP is generated through the use of a proton gradient and chemiosmosis. $C_6HO_6$, (Choice C) or glucose is a product formed during the light-independent reactions. Glucose is not a source of hydrogen ions. However, it does require the hydrogen ions from NADPH in order to be synthesized in the Calvin cycle.NADPH (Choice D) is a source of hydrogen ions in the Calvin cycle, where glucose is produced. This takes place in the light-independent reactions, however, and not in the light-dependent reactions of photosynthesis.
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