Question

During light reaction in photosynthesis, the following are formed.

• A. ATP and sugar
• B. hydrogen,$O_2$ and sugar
• C. ATP, hydrogen and $O_2$
• D. ATP, hydrogen and $O_2$ donor

Answer 1

The correct option is C ATP, hydrogen and $O_2$

Light reactions occur inside thylakoids. It is dependent upon light. It involves photolysis of water (breaking of water into $H_2$ and $O_2$ and production of assimilation power (NADPH and ATP). Electron released during photolysis of water are picked up by $P_{680}$ photocentre of photosystem II. From here electrons passes over series of carrier which include PQ, cytochrome b-f complex, and PC. While passing over cytochrome complex, the electron losses sufficient energy for creation of proton gradient and ATP from ADP and inorganic phosphate. From PC electron losses sufficient energy for creation of proton gradient and ATP from ADP and inorganic phosphate. From PC electron is picked by the trap center $P_{700}$of phtotsystem I, which pushes out electron after absorbing light energy. Electron passes over carriers Fes, ferredoxin and NADP reductase which gives electron to $NAD{P}^{+}$ for combing with $H^{+}$ to produce NADPH.
$NAD{P}^{+}2e^{-}+H^{+}\underset{NADPreductase}{\overset{}{\to }}NADPH$ , So, the correct answer is 'ATP, hydrogen and O2'.