Photosynthesis and Plant Metabolism (GATE)
Questions covering photosynthetic carbon fixation pathways (C3, C4, CAM), Calvin cycle enzymes and regulation, RuBisCo biochemistry, chloroplast development, and photorespiration in plants and photosynthetic organisms
Questions
How many ATP and NADH are generated by fixation of 1 molecule of CO2 by C4 plants?
- 3 ATP and 2 NADH
- 4 ATP and 3 NADH
- 5 ATP and 3 NADH
- 5 ATP and 2 NADH
Who coined the term Crassulacean Acid Metabolism (CAM) for carbon fixation pathway that evolved in some plants as an adaptation to arid condition?
- de Saussure
- Ranson and Thomas
- Aubert, E.
- Richards, H. M.
The presence of bundle sheath with chloroplast in the leaves which are granulated and lacking in starch is known as chloroplast dimorphism. Such feature is observed in
- hornwort
- wheat
- pineapple
- maize
RuBisCo enzyme needs a magnesium ion to be bound to the lysine in order to function. This magnesium ion is released from
- cytosol
- stroma
- thylakoid membrane
- thylakoid lumen
RuBisCo enzyme is the first enzyme involved in the first major step of carbon fixation. Which of the following organisms is never used in genetic engineering of RuBisCo ?
- Glaucospira Lagerheim
- Rhodospirillum rubrum
- Synechococcus elongatus
- Galdieria partita
Oxaloacetic acid is the first stable product formed during carbon fixation in
- wheat
- sorghum
- mango
- potato
Which enzyme catalyzes the conversion of ribose-5-phosphate (R5P) into ribulose-5-phosphate (Ru5P, RuP) in the regeneration stage of Calvin cycle?
- Transketolase
- Phosphopentose epimerase
- Phosphopentose isomerase
- Phosphoribulokinase
2-Carboxy-D-arabinitol 1-phosphate (CA1P) is synthesized by C4 plants like tobacco and beans in the night. Which of the following functions does it perform?
- Enhances the rate of photosynthesis
- Forms bonds with CO2 and helps in its storage
- Inhibits the catalytic activity of RuBisCo
- Incorporates more oxygen into RuBP
Which is known as an inhibitor of photosynthesis?
- Pyruvate reductase
- Glycolate oxidase
- 2-phosphoglycolate
- 3-phosphoglycerate
Under which condition can C3 cycle not operate in plants?
- High CO2
- Absence of oxygen
- High CO2 and absence of oxygen
- Low CO2 and presence of oxygen
Glutamine oxoglutarate aminotransferase (GOGAT) manufactures glutamate from glutamine and α-ketoglutarate. Ferredoxin-dependent GOGAT is strictly found in
- ferns
- rhodophytes
- cyanobacteria
- vascular plants
Which of the following is oxidized in the light phase of photosynthesis?
- CO2
- Water
- NADPH2
- NADP
What is the net gain of glyceraldehyde 3-phosphate in the regeneration step of Calvin cycle?
- 6
- 5
- 1
- 3
The golden 2 like (GLK) genes were discovered in maize in 2001. Which of the following functions do they perform?
- CA1P-phosphatase regulation
- Phosphoenol carboxylase regulation
- Chloroplast development
- NADP-malic enzyme regulation
Why is enzyme triosephosphate isomerase required in the regeneration step of Calvin cycle?
- Conversion of a G3P and a DHAP into fructose 6-phosphate (6C)
- Conversion of all of the G3P reversibly into dihydroxyacetone phosphate
- Synthesis of erythrose-4-phosphate
- Cleavage of sedoheptulose-1,7-bisphosphate into sedoheptulose-7-phosphate