1. The cyclic electron flow during photosynthesis in plants does not result into (a) production of NADPH,
(b) Production of ATP (c) Production of protons (d) none
2. The species having the highest reduction potential is (a) [ Mn – complex ] +4 (b) P680·+ (c) NADPH
(d) H2O
3. During plant photosynthesis concentration of protons increases in (a) stroma (b) lamelle (c) chloroplast (d) lumen
4. In photosynthesis by purple bacteria which step is the slowest ? (a) charge separation
(b) electron transfer from QA to QB (c) electron transfer from Cyt bc1 to (Chl)2·+
(d) electron transfer from pheophytin to QA
5. In photosynthesis photons raise __________ of electrons (a) reduction potential (b) oxidation potential (c) flow (d) none
6. Oxidation potential of DCPIP is ______ than water (a) higher (b) lower (c) same (d) none
7. Which one is not oriented towards lumen side ? (a) OEC (b) PC (c) Cytf (d) Cyt b6
8. Which sequence of steps can give ATP ? ( A – addition of pH 4 medium , B – removal of the medium by centrifugation , C – addition of pH 8 medium, D – addition of ADP + Pi , E – incubation for 2 hours )
(a) Chloroplast – C – E - B – D – A , (b) Chloroplast - A - E – B – C – D (c) Chloroplast – C – E - B – A – D and (d) Chloroplast - A - B – E – C – D
9. ATP synthase is located in (a) granal lamelle (b) stromal lamelle (c) lumen (d) stroma
10. Which statement is not true about OEC ? (a) It catalyzes the evolution of oxygen (b) It is oriented towards stromal side (c) It provides 4 electrons to PSII (d) It acts as a proton pump.
11. Which species accepts electrons from water in OEC ? (a) Tyr (b) [ Mn – complex ] 0
(c) [ Mn – complex ] +4 (d) P680·+
12. How many NADPH molecules are produced for each molecule of oxygen evolved ?
(a) 1 (b) 2 (c) 3 (d) 4
13. How many molecules of ATP are produced for each oxygen molecule evolved in photosynthesis ?
(a) 1 (b) 2 (c) 3 (d) 4
14. Under which condition electron flow during plant photosynthesis can become cyclic ?
(a) high [NADP] / [NADPH] (b) low [NADP] / [NADPH] (c) In presence of DCMU (d) In presence of DCPIP
2 comments:
Sir,
I have slight confusion in the number 6th question.
The question is about the comparison of oxidation potential between water and DCPIP.
2H2O + 2A (in the presence of light) gives 2AH2 + O2 (Hill reaction).
Where A is an electron acceptor like DCPIP.
In the reaction, we can see that DCPIP has been reduced. This means that its reduction potential is higher than that of the water. This also tells that DCPIP’s oxidation potential is lower than that of the water.
So I think that the correct answer will be: DCPIP has lower (instead of higher) oxidation potential than water.
Sir could you tell me what difference does it make when we add pH 8 medium and then put pH 4 medium instead of adding pH 4 medium and then add pH 8 medium (question number 8).
Hemant Raj Joshi
Dear Hemant :
Photons have done the trick. In dark DCPIP is not reduced. Tricky !!!
sorry for late response.
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