The light independent reactions are seen in:
I. | C3 carbon fixation |
II. | C4 carbon fixation |
III. | Crassulacean acid metabolism |
1. I and II only | 2. I and III only |
3. II and III only | 4. I, II and III |
In the light dependent reactions of photosynthesis:
1. | NADPH is reduced to NADP+ by the enzyme NADP reductase |
2. | initial carbon fixation takes place forming a 3 carbon compound. |
3. | ATP is not produced. |
4. | light is absorbed and energy is transported to reaction-center chlorophyll a |
The number of molecules of NADPH and ATP required respectively to reduce six molecules of carbon dioxide to glucose in Calvin cycle?
1. | 6 and 6 | 2. | 12 and 12 |
3. | 12 and 18 | 4. | 18 and 12 |
Identify the correct statement regarding the functioning of photosystem II?
1. | The reaction center is P700. |
2. | It works after PS I in non cyclic photophosphorylation. |
3. | Water splits and carbon dioxide is released. |
4. | The electron vacancies in P680 are filled by electrons derived from water. |
Consider the following two statements regarding RuBisCO:
I: | When carbon dioxide is the substrate, the product of the carboxylase reaction is finally two molecules of glycerate-3-phosphate. |
II: | When molecular oxygen is the substrate, the products of the oxygenase reaction are two molecules of phosphoglycolate. |
1. | Only I is correct | 2. | Only II is correct |
3. | Both I and II are correct | 4. | Both I and II are incorrect |
Photosystem I is directly associated with:
1. | passing electrons to plastoquinone |
2. | receiving electrons from plastocyanin |
3. | P680 as the chlorophyll a reaction-center |
4. | removal of electrons and protons from water |
Identify the correct statements regarding RuBisCO:
I: | It catalyzes the carboxylation of \(CO_2\) to ribulose 1,5-bisphosphate. |
II: | It initiates photorespiration when the \(CO_2/O_2\) ratio is low. |
III: | It catalyzes the reduction of two molecules of PGAL to form glucose. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
The products of non-cyclic photophosphorylation include:
1. | ATP and P700 | 2. | ATP and NADPH |
3. | ADP and NADP | 4. | P700 and P680 |
The and photosynthesis pathways are so called because the initial carbon fixation product in them are respectively:
1. | pyruvate; malate |
2. | malate; pyruvate |
3. | 3-phosphoglycerate; oxaloacetic acid |
4. | glyceraldehyde 3-phosphate; phospho-enol-pyruvate (PEP) |
The extra ATP required [as compared to NADPH] in Calvin cycle comes from:
1. | photosystem II | 2. | photosystem I |
3. | cyclic electron flow | 4. | non cyclic electron flow |