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All questions of Plant Nutrition for JAMB Exam
The splitting of water molecule is take place inside
a)Outer membraneb)Lumenc)Stromad)Inner membrane Correct answer is option 'B'. Can you explain this answer?
|
|
Vibhor Goyal answered |
Splitting of water takes place near PS II, located in the inner side of the thylakoid membrane.
Splitting of water releases oxygen in the atmosphere and generates a proton gradient across the thylakoid membrane.
The splitting of water molecules is associated with- a)PS II
- b)PS I
- c)Cyclic phosphorylation
- d)Non-cyclic phosphorylation
Correct answer is option 'A'. Can you explain this answer?
The splitting of water molecules is associated with
a)
PS II
b)
PS I
c)
Cyclic phosphorylation
d)
Non-cyclic phosphorylation
|
Swara Sarkar answered |
This is achieved by electrons available due to splitting of water. The splitting of water is associated with the PS II; water is split into H+, [O] and electrons.
In the half-leaf experiment of photosynthesis, KOH solution is used because- a)It provides O2 to the leaf.
- b)It provides moisture to the leaf.
- c)It helps in CO2 fixation.
- d)It absorbs CO2.
Correct answer is option 'D'. Can you explain this answer?
In the half-leaf experiment of photosynthesis, KOH solution is used because
a)
It provides O2 to the leaf.
b)
It provides moisture to the leaf.
c)
It helps in CO2 fixation.
d)
It absorbs CO2.
|
Krishna Iyer answered |
KOH (Potassium Hydroxide) absorbs carbon dioxide. The leaf inside the bottle containing KOH solution does not become blue-black when compared with the leaf which is exposed to atmospheric air. This shows that carbon dioxide is necessary for photosynthesis.
Can you explain the answer of this question below:Which range of wavelength (in nm) is called photosynthetically active radiation (PAR)?
- A:
400-700
- B:
760-10,000
- C:
100-390
- D:
390-430
The answer is a.
Which range of wavelength (in nm) is called photosynthetically active radiation (PAR)?
400-700
760-10,000
100-390
390-430
|
|
Krishna Iyer answered |
Photosynthetically active radiation. Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis.
During photochemical reaction of photosynthesis –- a)liberation of O2 takes place
- b)Formation of ATP and NADPH2 take place
- c)Liberation of O2, formation of ATP, and NADPH2 takes place
- d)Assimilation of CO2 takes place
Correct answer is option 'C'. Can you explain this answer?
During photochemical reaction of photosynthesis –
a)
liberation of O2 takes place
b)
Formation of ATP and NADPH2 take place
c)
Liberation of O2, formation of ATP, and NADPH2 takes place
d)
Assimilation of CO2 takes place
|
Momin Anam answered |
C is correct
The by product of photosynthesis is- a)CO2
- b)Oxygen
- c)Energy
- d)Sugar
Correct answer is option 'B'. Can you explain this answer?
The by product of photosynthesis is
a)
CO2
b)
Oxygen
c)
Energy
d)
Sugar
|
Rajni Kokate answered |
6(CO2) + 12(H2O) ----------> C6H12O6 +6(O2) + 6H2O
In photosynthesis phototrophs synthesize glucose and water and evolve O2 as by product
In photosynthesis phototrophs synthesize glucose and water and evolve O2 as by product
In higher plants, the shape of the chloroplast is- a)Reticulate
- b)Girdle-shaped
- c)Discoid
- d)Cup-shaped
Correct answer is option 'C'. Can you explain this answer?
In higher plants, the shape of the chloroplast is
a)
Reticulate
b)
Girdle-shaped
c)
Discoid
d)
Cup-shaped
|
EduRev JEE answered |
Chloroplasts are the green plastids which take part in photosynthesis and temporary or permanent storage of starch. These are discoid (disc-shaped) in higher plants with diameter of 4-6 μm and thickness of 2-4.μm.
Who described the first action spectrum for photosynthesis?- a)T. W. Engelmann
- b)Cornelius van Niel
- c)Joseph Priestley
- d)Julius von Sachs
Correct answer is option 'A'. Can you explain this answer?
Who described the first action spectrum for photosynthesis?
a)
T. W. Engelmann
b)
Cornelius van Niel
c)
Joseph Priestley
d)
Julius von Sachs
|
Arun Khanna answered |
Engelmann used a prism to split light into its spectral components, and then illuminated a green alga, Cladophora, placed in a suspension of aerobic bacteria. The bacteria were used to detect the sites of oxygen evolution.
He observed that bacteria mainly accumulated in the region of blue and red light of the split spectrum, thus giving the first action spectrum of photosynthesis.
Chlorophyll in chloroplasts is located in- a)Grana
- b)Pyrenoid
- c)Stroma
- d)Both grana and stroma
Correct answer is option 'A'. Can you explain this answer?
Chlorophyll in chloroplasts is located in
a)
Grana
b)
Pyrenoid
c)
Stroma
d)
Both grana and stroma
|
|
Gulzar Ahmad answered |
Grana are the stakes of thylakoids which possess green pigment called chlorophyll...
Element which helps in electron transport in the process of photosynthesis is- a)Zinc
- b)Molybdenum
- c)Boron
- d)Mangnese
Correct answer is option 'D'. Can you explain this answer?
Element which helps in electron transport in the process of photosynthesis is
a)
Zinc
b)
Molybdenum
c)
Boron
d)
Mangnese
|
Preeti Iyer answered |
During noncyclic electron flow the electron hole in P-680 is filled by electrons obtained by photolysis of water. As a result, there is an evolution of oxygen and the electron move through Mn-protein bound to PS II. In this transport Mn++ is oxidised to Mn+++ and then reduced to Mn++ in a cyclic manner. The manganese thus transfers electrons from water to photosystem II and thus plays an important role in electron transport in the process of photosynthesis.
C-4 plants are found among- a)Only gramineae
- b)Only monocot
- c)Only dicot
- d)Monocots as well as dicots
Correct answer is option 'D'. Can you explain this answer?
C-4 plants are found among
a)
Only gramineae
b)
Only monocot
c)
Only dicot
d)
Monocots as well as dicots
|
Rajat Kapoor answered |
A C4 plant is a plant that cycles carbon dioxide into four-carbon sugar compounds to enter into the Calvin cycle. These plants are very efficient in hot, dry climates and make a lot of energy. Many foods we eat are C4 plants, like corn, pineapple, and sugar cane.
Which pigment system ultimately donates e– for the reduction of NADP.- a)PS II
- b)PS I
- c)CO2
- d)Plastoquinone
Correct answer is option 'B'. Can you explain this answer?
Which pigment system ultimately donates e– for the reduction of NADP.
a)
PS II
b)
PS I
c)
CO2
d)
Plastoquinone
|
Navya Sengupta answered |
Ans.
The electrons from PS I may also pass onto an electron carrier and then combine with the hydrogen ions (from the water) to reduce NADP to NADPH. This reduced NADP is used in the next series of reactions.
ADP + iP = ATP in grana is called :–- a)Phosphorylation
- b)Oxidative phosphorylation
- c)Photophosphorylation
- d)Photolysis
Correct answer is option 'C'. Can you explain this answer?
ADP + iP = ATP in grana is called :–
a)
Phosphorylation
b)
Oxidative phosphorylation
c)
Photophosphorylation
d)
Photolysis
|
Stepway Academy answered |
Photophosphorylation is the conversion of ADP to ATP using the energy of sunlight by activation of PSII. This involves the splitting of the water molecule in oxygen and hydrogen protons (H+), a process known as photolysis.
Isotopes employed to study the process of photosynthesis reaction.- a)S35 and P32
- b)C14 and O18
- c)N14 and Co60
- d)N14 and O18
Correct answer is option 'B'. Can you explain this answer?
Isotopes employed to study the process of photosynthesis reaction.
a)
S35 and P32
b)
C14 and O18
c)
N14 and Co60
d)
N14 and O18
|
|
Awantika Gupta answered |
Correct reason is C14 and O18 was radioactive so it helped in study of photosynthesis.
The first stable product of photosynthesis in C-3 plants is :–- a)3-phosphoglyceric acid
- b)Dihydroxyacetone phosphate
- c)Fructose-1, 6 - diphosphate
- d)Ribulose-1, 5-di phosphate
Correct answer is option 'A'. Can you explain this answer?
The first stable product of photosynthesis in C-3 plants is :–
a)
3-phosphoglyceric acid
b)
Dihydroxyacetone phosphate
c)
Fructose-1, 6 - diphosphate
d)
Ribulose-1, 5-di phosphate
|
|
Vartika Shukla answered |
The first stable product of CO2 fixation in C3 plants is a three-carbon organic acid. The enzyme ribulose-1,5-bisphosphate carboxylase–oxygenase (RUBISCO) combines CO2 with the phosphosugar ribulose 1,5-bisphosphate to form two molecules of 3-phosphoglyceric acid. In contrast, carbon fixation in C4 plants results in the formation of four-carbon organic acids, aspartate and malate, as the first stable product of carbon fixation
"Kranz Anatomy" is found in- a)Flower
- b)Seed
- c)Leaves
- d)Stem
Correct answer is option 'C'. Can you explain this answer?
"Kranz Anatomy" is found in
a)
Flower
b)
Seed
c)
Leaves
d)
Stem
|
|
Gopikas S answered |
Kranz anatomy is a special structure in the leaves of plants, that have a C4 pathway of carbon dioxide fixation. The leaves contain a ring of mesophyll cells, containing a few small chloroplasts concerned with the initial fixing of carbon dioxide, surrounding a sheath of parenchyma cells (the bundle sheath) which has large chloroplasts involved in the Calvin cycle. C4 photosynthesis is found in many plant species, mostly in monocots (such as maize, sugar cane and several grasses) but also in many dicots (such as amaranth and flaveria).
In PSI, the reaction centre the chlorophyll a has an absorption peak at- a)780nm
- b)700nm
- c)680nm
- d)800nm
Correct answer is option 'B'. Can you explain this answer?
In PSI, the reaction centre the chlorophyll a has an absorption peak at
a)
780nm
b)
700nm
c)
680nm
d)
800nm
|
|
Vartika Shukla (NEET Aspirant) answered |
In PS-I, the reaction centre chlorophyll a has an absorption peak at 700 nm, hence, is called P 700 while in PS-H, it has absorption maxima at 680 nm, so is called P 680.
so the correct answer is b) 700nm
so the correct answer is b) 700nm
The first step in photosynthesis is- a)Joining of three carbon atoms to from glucose
- b)Formation of ATP
- c)Ionization of water
- d)Excitement of an electron of chlorophyll by a photon of light.
Correct answer is option 'D'. Can you explain this answer?
The first step in photosynthesis is
a)
Joining of three carbon atoms to from glucose
b)
Formation of ATP
c)
Ionization of water
d)
Excitement of an electron of chlorophyll by a photon of light.
|
Nandini Patel answered |
The energy from the sun, raises an energy level in the chlorophyll molecule, causing electrons to leave the molecule and travel along the electron transport chain (ETC) in a series of oxidation and reductions. In doing so it releases energy converting ADP+Pi into ATP. Photolysis (splitting of water) occurs, and the electrons produced, replace those lost. This is the Light Dependant stage as it relies on light energy
In photosynthesis, hydrogen is transferred from the light reactions to dark reactions by :–- a)DPN
- b)DNA
- c)ATP
- d)NADP
Correct answer is option 'D'. Can you explain this answer?
In photosynthesis, hydrogen is transferred from the light reactions to dark reactions by :–
a)
DPN
b)
DNA
c)
ATP
d)
NADP
|
Bs Academy answered |
Photosynthesis occurs in two stages, light reaction, and dark reaction. During the light reaction reduced NADPH2 and ATP are synthesized. These products are used subsequently to reduce carbon dioxide into sugars. The purpose of ATP in photosynthesis is to transfer energy from light reaction to dark reaction. The purpose of NADP is to transfer hydrogen from light reaction to dark reaction in the form of reduced NADPH2.
Solarisation is- a)Effect of solar light
- b)Destruction of chlorophyll
- c)Formation of chlorophyll
- d)Utilisation of sunlight
Correct answer is option 'B'. Can you explain this answer?
Solarisation is
a)
Effect of solar light
b)
Destruction of chlorophyll
c)
Formation of chlorophyll
d)
Utilisation of sunlight
|
Muskaan Dasgupta answered |
Solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. This phenomenon is commonly observed in plants that grow in areas with high solar radiation. Here is a detailed explanation of the process:
Explanation:
Chlorophyll is the green pigment present in the leaves of plants. It plays a crucial role in photosynthesis, which is the process by which plants convert sunlight into energy. However, prolonged exposure to sunlight can damage the chlorophyll molecules, leading to their destruction. This process is known as solarisation.
Solarisation occurs due to the following reasons:
1. High intensity of sunlight: Plants that grow in areas with high solar radiation are more prone to solarisation. This is because the intensity of sunlight in these areas is much higher than in other regions.
2. Extended exposure to sunlight: The longer a plant is exposed to sunlight, the greater the damage to its chlorophyll molecules. This is why solarisation is more common during the summer months, when the days are longer and the sun is more intense.
Effects of solarisation:
1. Reduced photosynthesis: Solarisation damages the chlorophyll molecules, which reduces the plant's ability to carry out photosynthesis. This can lead to stunted growth and reduced yield.
2. Loss of colour: As the chlorophyll molecules are destroyed, the leaves of the plant lose their green colour and turn yellow or brown.
3. Increased susceptibility to pests and diseases: Plants that have been solarised are more susceptible to pests and diseases, as their weakened state makes them more vulnerable to attack.
Prevention of solarisation:
1. Shade: Providing shade to the plants can reduce their exposure to sunlight and prevent solarisation. This can be done by using shade cloth or by planting the crops under trees.
2. Watering: Regular watering can help cool down the plants and reduce the damage caused by solarisation.
3. Timely harvesting: Harvesting the crops before they are fully mature can reduce their exposure to sunlight and prevent solarisation.
In conclusion, solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. It can have a negative impact on plant growth and yield, and can be prevented by providing shade, regular watering, and timely harvesting.
Explanation:
Chlorophyll is the green pigment present in the leaves of plants. It plays a crucial role in photosynthesis, which is the process by which plants convert sunlight into energy. However, prolonged exposure to sunlight can damage the chlorophyll molecules, leading to their destruction. This process is known as solarisation.
Solarisation occurs due to the following reasons:
1. High intensity of sunlight: Plants that grow in areas with high solar radiation are more prone to solarisation. This is because the intensity of sunlight in these areas is much higher than in other regions.
2. Extended exposure to sunlight: The longer a plant is exposed to sunlight, the greater the damage to its chlorophyll molecules. This is why solarisation is more common during the summer months, when the days are longer and the sun is more intense.
Effects of solarisation:
1. Reduced photosynthesis: Solarisation damages the chlorophyll molecules, which reduces the plant's ability to carry out photosynthesis. This can lead to stunted growth and reduced yield.
2. Loss of colour: As the chlorophyll molecules are destroyed, the leaves of the plant lose their green colour and turn yellow or brown.
3. Increased susceptibility to pests and diseases: Plants that have been solarised are more susceptible to pests and diseases, as their weakened state makes them more vulnerable to attack.
Prevention of solarisation:
1. Shade: Providing shade to the plants can reduce their exposure to sunlight and prevent solarisation. This can be done by using shade cloth or by planting the crops under trees.
2. Watering: Regular watering can help cool down the plants and reduce the damage caused by solarisation.
3. Timely harvesting: Harvesting the crops before they are fully mature can reduce their exposure to sunlight and prevent solarisation.
In conclusion, solarisation is the process of destruction of chlorophyll due to prolonged exposure to sunlight. It can have a negative impact on plant growth and yield, and can be prevented by providing shade, regular watering, and timely harvesting.
Internally, the chloroplast is divided into two parts – the membrane system and the fluid portion called stroma. Labour is equally divided between the two parts with each responsible for a particular function of photosynthesis leading to the formation of sugars. Which part(s) is/are involved in the synthesis of ATP and NADPH?
- a)Both membrane system and stroma
- b)Stroma
- c)Neither membrane system nor stroma
- d)Membrane system
Correct answer is option 'D'. Can you explain this answer?
Internally, the chloroplast is divided into two parts – the membrane system and the fluid portion called stroma. Labour is equally divided between the two parts with each responsible for a particular function of photosynthesis leading to the formation of sugars. Which part(s) is/are involved in the synthesis of ATP and NADPH?
a)
Both membrane system and stroma
b)
Stroma
c)
Neither membrane system nor stroma
d)
Membrane system
|
Gaurav Kumar answered |
There is clear division of labour within the chloroplast. the membrane system is responsible for the light reaction ( trapping light energy and synthesis of ATP and NADPH) while dark reaction i.e., enzymatic reactions for the reduction of carbon dioxide into sugar using ATP and NADPH take place in the stroma.
Who demonstrated the importance of sunlight for the process of photosynthesis?- a)Robert Hill
- b)Engelmann
- c)Jan Ingenhousz
- d)Joseph Priestley
Correct answer is option 'C'. Can you explain this answer?
Who demonstrated the importance of sunlight for the process of photosynthesis?
a)
Robert Hill
b)
Engelmann
c)
Jan Ingenhousz
d)
Joseph Priestley
|
|
Pooja Mehta answered |
Jan Ingenhousz is best known for his discovery of photosynthesis, the process by which green plants absorb carbon dioxide in the presence of sunlight and release oxygen. Through an ingenious series of experiments, Ingenhousz proved that plant leaves need sunlight rather than heat in order to produce oxygen.
Which occurs during the light reaction of photosynthesis- a)Chlorophyll is produced
- b)Water splits to form 2H+ & O2
- c)CO2 is given off as a waste
- d)Sugar is formed from CO2 and water
Correct answer is option 'B'. Can you explain this answer?
Which occurs during the light reaction of photosynthesis
a)
Chlorophyll is produced
b)
Water splits to form 2H+ & O2
c)
CO2 is given off as a waste
d)
Sugar is formed from CO2 and water
|
Om Desai answered |
The chlorophyll pigments which are excited give up their electrons and to compensate for the loss of electrons, water is split to release four H+ ions and four electrons and O2. The electrons that are lost from the PSII enter into an electron transfer chain or ETC.
During photosynthesis when PGA is changed into phosphoglyceraldehyde which of the following reaction occur :–- a)Oxidation
- b)Reduction
- c)Electrolysis
- d)Hydrolysis
Correct answer is option 'B'. Can you explain this answer?
During photosynthesis when PGA is changed into phosphoglyceraldehyde which of the following reaction occur :–
a)
Oxidation
b)
Reduction
c)
Electrolysis
d)
Hydrolysis
|
Arjun Chauhan answered |
The conversion of PGA (3-phosphoglycerate) into phosphoglyceraldehyde (PGAL or G3P, glyceraldehyde-3-phosphate) is the sixth step of the Calvin cycle of photosynthesis, and it involves the reduction of PGA by NADPH and ATP. The reaction can be written as:
PGA + NADPH + H+ + ATP → PGAL + NADP+ + ADP + Pi
This reaction is catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which uses the reducing power of NADPH to add a phosphate group to PGA and then remove a hydride ion from the molecule, producing PGAL. This reaction is also known as the reduction phase of the Calvin cycle, as it involves the transfer of electrons from NADPH to PGA, reducing it to PGAL, which can then be used to make glucose or other organic molecules.
PGA + NADPH + H+ + ATP → PGAL + NADP+ + ADP + Pi
This reaction is catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which uses the reducing power of NADPH to add a phosphate group to PGA and then remove a hydride ion from the molecule, producing PGAL. This reaction is also known as the reduction phase of the Calvin cycle, as it involves the transfer of electrons from NADPH to PGA, reducing it to PGAL, which can then be used to make glucose or other organic molecules.
Photorespiration does not occur in- a)C4 plants
- b)C3 plants
- c)Algae
- d)Bacteria
Correct answer is option 'A'. Can you explain this answer?
Photorespiration does not occur in
a)
C4 plants
b)
C3 plants
c)
Algae
d)
Bacteria
|
|
Awantika Gupta answered |
Photorespiration is a wastefull process because it doesn't synthesis ATP.
but in new ncert it is mentioned that the requirements of photorespiration is not known yet.
but in new ncert it is mentioned that the requirements of photorespiration is not known yet.
The enzyme which catalyzes the photosynthetic C4 cycle is- a)RUDP carboxylase
- b)PEP carboxylase
- c)Carbonic anhydrase
- d)None of these
Correct answer is option 'B'. Can you explain this answer?
The enzyme which catalyzes the photosynthetic C4 cycle is
a)
RUDP carboxylase
b)
PEP carboxylase
c)
Carbonic anhydrase
d)
None of these
|
|
Shalini Shalu answered |
PEP carboxylate enzyme of C4 carries out carboxylation of phosphoenolpyruvate into oxaloacetate..hence the ans is option B
Which of the following is likely to be the first substance that a green plant makes in photosynthesis :–- a)A simple sugar
- b)Starch
- c)Fats
- d)Proteins
Correct answer is option 'A'. Can you explain this answer?
Which of the following is likely to be the first substance that a green plant makes in photosynthesis :–
a)
A simple sugar
b)
Starch
c)
Fats
d)
Proteins
|
Lead Academy answered |
In the majority of the plants, the first stable intermediate of carbon dioxide reduction is a three-carbon compound. Hence, this type of carbon reduction is called as C3 cycle. In C3 cycle, the initial carboxylation is brought about by RuBisCo, which carboxylates Ribulose 1,5 bisphosphate (RUBP) into phosphoglyceric acid. The phosphoglyceric acid is later on reduced to phosphoglyceraldehyde, which is used to synthesize sugars and recycle RUBP. Simple sugars like glucose and fructose are first produced. They are converted to sucrose for transportation and later on into starch for long term storage.
Number of ATP molecules requried for regeneration phase of RUBP during synthesis of 1 glucose molecule.- a)6
- b)12
- c)18
- d)30
Correct answer is option 'A'. Can you explain this answer?
Number of ATP molecules requried for regeneration phase of RUBP during synthesis of 1 glucose molecule.
a)
6
b)
12
c)
18
d)
30
|
Pooja Choudhary answered |
Ans.
To create 1 surplus G3P requires 3 carbons, and therefore 3 turns of the Calvin cycle. To make one glucose molecule (which can be created from 2 G3P molecules) would require 6 turns of the Calvin cycle.
What is the first stable intermediate product of photosynthesis :–- a)Glucose
- b)Formaldehyde
- c)phosphoglyceric acid
- d)PGAL
Correct answer is option 'C'. Can you explain this answer?
What is the first stable intermediate product of photosynthesis :–
a)
Glucose
b)
Formaldehyde
c)
phosphoglyceric acid
d)
PGAL
|
Moumita Chauhan answered |
**The first stable intermediate product of photosynthesis is phosphoglyceric acid (PGA).**
**Explanation:**
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. It occurs in the chloroplasts of plant cells.
During photosynthesis, a series of complex reactions take place, which can be divided into two main stages: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle).
The light-dependent reactions occur in the thylakoid membranes of the chloroplasts and involve the conversion of light energy into chemical energy in the form of ATP and NADPH. These energy-rich molecules are then used in the light-independent reactions.
The light-independent reactions, also known as the Calvin cycle, occur in the stroma of the chloroplasts. These reactions involve the fixation of carbon dioxide (CO2) and the synthesis of glucose.
**The Calvin cycle can be summarized into three main stages:**
1. **Carbon Fixation:**
- The enzyme RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyzes the reaction between carbon dioxide (CO2) and a 5-carbon compound called ribulose-1,5-bisphosphate (RuBP).
- This reaction results in the formation of an unstable 6-carbon compound, which quickly breaks down into two molecules of 3-phosphoglycerate (PGA).
- PGA is the first stable intermediate product of photosynthesis.
2. **Reduction:**
- Each molecule of PGA is then converted into a molecule of glyceraldehyde-3-phosphate (G3P) through a series of reactions.
- This conversion requires ATP and NADPH, which were produced during the light-dependent reactions.
- Some of the G3P molecules are used to regenerate RuBP, while others are used to produce glucose and other organic compounds.
3. **Regeneration:**
- The remaining G3P molecules are rearranged and combined to regenerate RuBP, which can then react with more carbon dioxide in the carbon fixation stage.
- This regeneration step is essential to sustain the Calvin cycle and continue the synthesis of glucose.
In summary, phosphoglyceric acid (PGA) is the first stable intermediate product of photosynthesis. It is formed through the carbon fixation stage of the Calvin cycle, where carbon dioxide is fixed and converted into PGA. This molecule is then further processed and converted into glyceraldehyde-3-phosphate (G3P), which is used to produce glucose and regenerate the starting compound, ribulose-1,5-bisphosphate (RuBP).
**Explanation:**
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy from the sun into chemical energy in the form of glucose. It occurs in the chloroplasts of plant cells.
During photosynthesis, a series of complex reactions take place, which can be divided into two main stages: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle).
The light-dependent reactions occur in the thylakoid membranes of the chloroplasts and involve the conversion of light energy into chemical energy in the form of ATP and NADPH. These energy-rich molecules are then used in the light-independent reactions.
The light-independent reactions, also known as the Calvin cycle, occur in the stroma of the chloroplasts. These reactions involve the fixation of carbon dioxide (CO2) and the synthesis of glucose.
**The Calvin cycle can be summarized into three main stages:**
1. **Carbon Fixation:**
- The enzyme RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) catalyzes the reaction between carbon dioxide (CO2) and a 5-carbon compound called ribulose-1,5-bisphosphate (RuBP).
- This reaction results in the formation of an unstable 6-carbon compound, which quickly breaks down into two molecules of 3-phosphoglycerate (PGA).
- PGA is the first stable intermediate product of photosynthesis.
2. **Reduction:**
- Each molecule of PGA is then converted into a molecule of glyceraldehyde-3-phosphate (G3P) through a series of reactions.
- This conversion requires ATP and NADPH, which were produced during the light-dependent reactions.
- Some of the G3P molecules are used to regenerate RuBP, while others are used to produce glucose and other organic compounds.
3. **Regeneration:**
- The remaining G3P molecules are rearranged and combined to regenerate RuBP, which can then react with more carbon dioxide in the carbon fixation stage.
- This regeneration step is essential to sustain the Calvin cycle and continue the synthesis of glucose.
In summary, phosphoglyceric acid (PGA) is the first stable intermediate product of photosynthesis. It is formed through the carbon fixation stage of the Calvin cycle, where carbon dioxide is fixed and converted into PGA. This molecule is then further processed and converted into glyceraldehyde-3-phosphate (G3P), which is used to produce glucose and regenerate the starting compound, ribulose-1,5-bisphosphate (RuBP).
Fixation of 1 CO2 requires :–- a)6NADPH2 & 3ATP
- b)2NADP.H2 & 3ATP
- c)4 NADP.H2 & 3ATP
- d)5 NADP.H2 & 3ATP
Correct answer is option 'B'. Can you explain this answer?
Fixation of 1 CO2 requires :–
a)
6NADPH2 & 3ATP
b)
2NADP.H2 & 3ATP
c)
4 NADP.H2 & 3ATP
d)
5 NADP.H2 & 3ATP
|
|
Pooja Shah answered |
The Calvin cycle has three stages.
1)carbon fixation
2)reduction
3)regeneration.
At the end of each Calvin cycle net gain is 9ATP and 6 NADPH2.In each Calvin cycle, 3 CO2 molecules are fixed with RuBP to form 2 molecules of 3PGA in the first step. Later two molecules of 3PGA through a series of reactions regenerate 2RuBP in the third stage. So, for the fixation of one CO2 carbon dioxide molecule through the Calvin cycle requires 3ATP and 2NADPH2.
So, the correct answer is 'option B'.
1)carbon fixation
2)reduction
3)regeneration.
At the end of each Calvin cycle net gain is 9ATP and 6 NADPH2.In each Calvin cycle, 3 CO2 molecules are fixed with RuBP to form 2 molecules of 3PGA in the first step. Later two molecules of 3PGA through a series of reactions regenerate 2RuBP in the third stage. So, for the fixation of one CO2 carbon dioxide molecule through the Calvin cycle requires 3ATP and 2NADPH2.
So, the correct answer is 'option B'.
Which of the following stages of calvin cycle are in correct order?- a)Carboxylation, reduction, regeneration
- b)Regeneration,carboxylation, reduction
- c)Regeneration,reduction,carboxylation
- d)Carboxylation,regeneration,reduction
Correct answer is option 'A'. Can you explain this answer?
Which of the following stages of calvin cycle are in correct order?
a)
Carboxylation, reduction, regeneration
b)
Regeneration,carboxylation, reduction
c)
Regeneration,reduction,carboxylation
d)
Carboxylation,regeneration,reduction
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Smruti Sucharita answered |
##ncert refer kro yrr... directly Diya hua h..
Dark fixation of CO2 in CAM plants is called ocification because it produces- a)Tartaric acid
- b)Oxaloacetic acid
- c)Malic acid
- d)Formic acid
Correct answer is option 'C'. Can you explain this answer?
Dark fixation of CO2 in CAM plants is called ocification because it produces
a)
Tartaric acid
b)
Oxaloacetic acid
c)
Malic acid
d)
Formic acid
|
|
Gopikas S answered |
The principal metabolic feature of CAM plants is assimilation of CO2 at night into malic acid which is stored in the vacuole. Malate is generated in the reaction catalyzed by PEP carboxylase and PEP is, in turn, generated by degradation of starch or soluble sugars. During the day, malate is released from the vacuole and is decarboxylated to provide CO2 for fixation in the Benson–Calvin cycle behind closed stomata. Starch and sugars are then resynthesized .
Photophosphorylation is the process in which- a)CO2 and O2 unite
- b)Phosphoglyceric acid is produced
- c)Aspartic acid is formed
- d)Light energy is converted in to chemical energy by production of ATP
Correct answer is option 'D'. Can you explain this answer?
Photophosphorylation is the process in which
a)
CO2 and O2 unite
b)
Phosphoglyceric acid is produced
c)
Aspartic acid is formed
d)
Light energy is converted in to chemical energy by production of ATP
|
|
Vartika shukla answered |
Phosphorylation: A biochemical process that involves the addition of phosphate to an organic compound. Examples include the addition of phosphate to glucose to produce glucose monophosphate and the addition of phosphate to adenosine diphosphate (ADP) to form adenosine triphosphate (ATP). Phosphorylation is carried out through the action of enzymes known as phosphotransferases or kinases.
The electron ejected by P680 in light reaction is initially accepted by- a)Plastoquinone
- b)ATP
- c)Ferredoxin
- d)P-700
Correct answer is option 'A'. Can you explain this answer?
The electron ejected by P680 in light reaction is initially accepted by
a)
Plastoquinone
b)
ATP
c)
Ferredoxin
d)
P-700
|
Rajeev Sharma answered |
During the light reaction, the path of the electron has been elucidated in the Z-scheme. It is named so because of its shape and was first proposed by Hill and Bendall in 1960. The electron released by reaction center of photosystem II i.e., P680 moves uphill and reduces pheophytin, a nonmagnesium chlorophyll a molecule. From pheophytin, electrons are accepted by plastoquinone which requires two electrons for complete reduction. It also accepts two protons from the stromal side of thylakoid membrane and becomes reduced to PQH2 after accepting 2 electrons and 2 protons. It is the only carrier in the photosynthetic electron transport chain, which can bind both electrons and protons.
Carbon dioxide acceptor in C4 plants is :–- a)Phosphoenol pyruvic acid (PEP)
- b)Ribulose-1, 5 - di phosphate
- c)NADP
- d)Ribulose-5 - phosphate
Correct answer is option 'A'. Can you explain this answer?
Carbon dioxide acceptor in C4 plants is :–
a)
Phosphoenol pyruvic acid (PEP)
b)
Ribulose-1, 5 - di phosphate
c)
NADP
d)
Ribulose-5 - phosphate
|
|
Debolina Desai answered |
Carbon Dioxide Acceptor in C4 Plants: Phosphoenol Pyruvic Acid (PEP)
In C4 plants, carbon dioxide (CO2) is initially fixed into a four-carbon compound called oxaloacetate (OAA) in the mesophyll cells of the leaves. The enzyme responsible for this initial fixation is phosphoenolpyruvate carboxylase (PEP carboxylase).
1. C4 Photosynthesis
C4 plants have evolved an efficient mechanism called C4 photosynthesis to overcome the limitations of the enzyme Rubisco, which has a low affinity for CO2 and can also catalyze reactions with oxygen, leading to photorespiration. C4 plants have specialized leaf anatomy, with two types of cells: mesophyll cells and bundle sheath cells.
2. Mesophyll Cells
In C4 plants, CO2 is first fixed into a three-carbon compound called phosphoenolpyruvate (PEP) by the enzyme PEP carboxylase in the mesophyll cells. This process occurs in the presence of ATP, and the reaction forms a four-carbon compound called oxaloacetate (OAA). This initial fixation of CO2 occurs in the mesophyll cells and is independent of light.
3. PEP Carboxylase
PEP carboxylase is an enzyme found in the mesophyll cells of C4 plants. It has a higher affinity for CO2 than Rubisco and does not catalyze reactions with oxygen. PEP carboxylase is not inhibited by oxygen and has a higher optimal temperature than Rubisco, allowing C4 plants to efficiently fix CO2 even under high temperatures.
4. Role of PEP in C4 Plants
The oxaloacetate (OAA) formed in the mesophyll cells is then converted into malate or aspartate, which can be transported to the bundle sheath cells, where the Calvin cycle takes place. In the bundle sheath cells, malate or aspartate is decarboxylated, releasing CO2, which is then fixed by Rubisco in the Calvin cycle.
5. Advantages of C4 Photosynthesis
C4 plants have several advantages over C3 plants (plants that use the Calvin cycle for photosynthesis):
- Increased efficiency in carbon fixation, especially under high temperature and light conditions
- Reduced photorespiration, leading to higher rates of photosynthesis and growth
- Ability to grow in environments with limited water availability and high temperatures, such as tropical areas
Overall, the carbon dioxide acceptor in C4 plants is phosphoenolpyruvate (PEP), which is fixed into oxaloacetate (OAA) by the enzyme PEP carboxylase in the mesophyll cells. This initial fixation of CO2 allows C4 plants to overcome the limitations of Rubisco and efficiently perform photosynthesis even under challenging environmental conditions.
In C4 plants, carbon dioxide (CO2) is initially fixed into a four-carbon compound called oxaloacetate (OAA) in the mesophyll cells of the leaves. The enzyme responsible for this initial fixation is phosphoenolpyruvate carboxylase (PEP carboxylase).
1. C4 Photosynthesis
C4 plants have evolved an efficient mechanism called C4 photosynthesis to overcome the limitations of the enzyme Rubisco, which has a low affinity for CO2 and can also catalyze reactions with oxygen, leading to photorespiration. C4 plants have specialized leaf anatomy, with two types of cells: mesophyll cells and bundle sheath cells.
2. Mesophyll Cells
In C4 plants, CO2 is first fixed into a three-carbon compound called phosphoenolpyruvate (PEP) by the enzyme PEP carboxylase in the mesophyll cells. This process occurs in the presence of ATP, and the reaction forms a four-carbon compound called oxaloacetate (OAA). This initial fixation of CO2 occurs in the mesophyll cells and is independent of light.
3. PEP Carboxylase
PEP carboxylase is an enzyme found in the mesophyll cells of C4 plants. It has a higher affinity for CO2 than Rubisco and does not catalyze reactions with oxygen. PEP carboxylase is not inhibited by oxygen and has a higher optimal temperature than Rubisco, allowing C4 plants to efficiently fix CO2 even under high temperatures.
4. Role of PEP in C4 Plants
The oxaloacetate (OAA) formed in the mesophyll cells is then converted into malate or aspartate, which can be transported to the bundle sheath cells, where the Calvin cycle takes place. In the bundle sheath cells, malate or aspartate is decarboxylated, releasing CO2, which is then fixed by Rubisco in the Calvin cycle.
5. Advantages of C4 Photosynthesis
C4 plants have several advantages over C3 plants (plants that use the Calvin cycle for photosynthesis):
- Increased efficiency in carbon fixation, especially under high temperature and light conditions
- Reduced photorespiration, leading to higher rates of photosynthesis and growth
- Ability to grow in environments with limited water availability and high temperatures, such as tropical areas
Overall, the carbon dioxide acceptor in C4 plants is phosphoenolpyruvate (PEP), which is fixed into oxaloacetate (OAA) by the enzyme PEP carboxylase in the mesophyll cells. This initial fixation of CO2 allows C4 plants to overcome the limitations of Rubisco and efficiently perform photosynthesis even under challenging environmental conditions.
In C4 pathway the fixation of CO2 by PEPCase occurs in- a)Palisade tissue
- b)Mesophyll
- c)Bundle sheath
- d)Gaurd cell
Correct answer is option 'B'. Can you explain this answer?
In C4 pathway the fixation of CO2 by PEPCase occurs in
a)
Palisade tissue
b)
Mesophyll
c)
Bundle sheath
d)
Gaurd cell
|
|
Ajay Yadav answered |
In the C4 pathway, initial carbon fixation takes place in mesophyll cells and the Calvin cycle takes place in bundle-sheath cells. PEP carboxylase attaches an incoming carbon dioxide molecul to the three-carbon molecule PEP, producing oxaloacetate (a four-carbon molecule).
Chloroplast is present in bundle sheath cells of- a)C3 - plants
- b)C4 plants
- c)CAM plants
- d)Photorespiring plants
Correct answer is option 'B'. Can you explain this answer?
Chloroplast is present in bundle sheath cells of
a)
C3 - plants
b)
C4 plants
c)
CAM plants
d)
Photorespiring plants
|
Top Rankers answered |
The thick walled bundle sheath cells present around vascular bundles in the shape of a ring in C4 plants have chloroplast. The bundle sheath cells have agranal chloroplast and fix carbon dioxide with the help of RuBisCO enzyme. The thin walled mesophyll cells carry out initial carbon dioxide fixation with the help of PEP carboxylase enzyme. This special arrangement of cells and presence of dimorphic chloroplasts helps in minimizing photorespiration in C4 plants.
PGA as the first CO2 fixation product was discovered in photosynthesis of- a)Angiosperm
- b)Bryophytes
- c)Algae
- d)Gymnosperm
Correct answer is option 'C'. Can you explain this answer?
PGA as the first CO2 fixation product was discovered in photosynthesis of
a)
Angiosperm
b)
Bryophytes
c)
Algae
d)
Gymnosperm
|
Abhiram Basu answered |
Photosynthesis and CO2 fixation
Photosynthesis is a process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into organic compounds and oxygen. This process is essential for life on earth as it produces the oxygen that we breathe and provides food for organisms that cannot produce their own.
CO2 fixation is the process by which carbon dioxide is transformed into an organic molecule that can be used by living organisms. This process is important because carbon dioxide is an essential component of the atmosphere, but it is not readily available to most organisms in its gaseous form.
PGA as the first CO2 fixation product
PGA (phosphoglyceric acid) is the first stable product of CO2 fixation in photosynthesis. It is formed when carbon dioxide combines with a five-carbon sugar called ribulose bisphosphate (RuBP) in a reaction catalyzed by the enzyme Rubisco (ribulose bisphosphate carboxylase/oxygenase).
Discovery of PGA
The discovery of PGA as the first CO2 fixation product was made by Melvin Calvin and his colleagues in the 1940s. They used radioactive carbon-14 to trace the movement of carbon through the photosynthetic process and discovered that PGA was the first stable product of CO2 fixation.
Source of PGA
PGA is produced in the stroma of the chloroplasts in plant cells. It is then used to make glucose and other organic compounds through a series of enzyme-catalyzed reactions known as the Calvin cycle.
Role of algae in PGA discovery
Algae played a crucial role in the discovery of PGA as the first CO2 fixation product. Algae are photosynthetic organisms that are capable of fixing carbon dioxide in a similar way to plants. They were used by Calvin and his colleagues as a model system to study photosynthesis and CO2 fixation.
Conclusion
In conclusion, PGA was discovered as the first CO2 fixation product in photosynthesis by Melvin Calvin and his colleagues in the 1940s. This discovery was made using algae as a model system and has since been confirmed in plants and other photosynthetic organisms.
Photosynthesis is a process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into organic compounds and oxygen. This process is essential for life on earth as it produces the oxygen that we breathe and provides food for organisms that cannot produce their own.
CO2 fixation is the process by which carbon dioxide is transformed into an organic molecule that can be used by living organisms. This process is important because carbon dioxide is an essential component of the atmosphere, but it is not readily available to most organisms in its gaseous form.
PGA as the first CO2 fixation product
PGA (phosphoglyceric acid) is the first stable product of CO2 fixation in photosynthesis. It is formed when carbon dioxide combines with a five-carbon sugar called ribulose bisphosphate (RuBP) in a reaction catalyzed by the enzyme Rubisco (ribulose bisphosphate carboxylase/oxygenase).
Discovery of PGA
The discovery of PGA as the first CO2 fixation product was made by Melvin Calvin and his colleagues in the 1940s. They used radioactive carbon-14 to trace the movement of carbon through the photosynthetic process and discovered that PGA was the first stable product of CO2 fixation.
Source of PGA
PGA is produced in the stroma of the chloroplasts in plant cells. It is then used to make glucose and other organic compounds through a series of enzyme-catalyzed reactions known as the Calvin cycle.
Role of algae in PGA discovery
Algae played a crucial role in the discovery of PGA as the first CO2 fixation product. Algae are photosynthetic organisms that are capable of fixing carbon dioxide in a similar way to plants. They were used by Calvin and his colleagues as a model system to study photosynthesis and CO2 fixation.
Conclusion
In conclusion, PGA was discovered as the first CO2 fixation product in photosynthesis by Melvin Calvin and his colleagues in the 1940s. This discovery was made using algae as a model system and has since been confirmed in plants and other photosynthetic organisms.
In sugarcane, CO2 is fixed in malic acid with the help of enzyme- a)Ribulose phosphate kinase
- b)RuBP carboxylase
- c)Fructose phosphotase
- d)PEP carboxylase
Correct answer is option 'D'. Can you explain this answer?
In sugarcane, CO2 is fixed in malic acid with the help of enzyme
a)
Ribulose phosphate kinase
b)
RuBP carboxylase
c)
Fructose phosphotase
d)
PEP carboxylase
|
|
Jay Kumar answered |
In C4 plants, Carbon dioxide is fixed in malic acid with the help of enzyme phosphoenel pyruvate (PEP). Malic acid is a four carbon compound that later change into oxyloacetic acid.
All the reactions from the reduction of CO2 to the formation of sugar are included in :–- a)Light reaction
- b)Photolysis
- c)Dark reaction
- d)Hill reaction
Correct answer is option 'C'. Can you explain this answer?
All the reactions from the reduction of CO2 to the formation of sugar are included in :–
a)
Light reaction
b)
Photolysis
c)
Dark reaction
d)
Hill reaction
|
|
Khusht Pandey answered |
Photosynthesis comprises of light phase and dark phase
during light phase reducing power and assimilatory power are synthesized which are used in dark phase to reduce Co2 to carbohydrates
the dark phase comprises of initial carboxylation reaction, reduction of phosphoglyceric acid to phosphoglyceraldehyde and synthesis of carbohydrate and regeneration of ribulose 1,5 diphosphate from phosphoglyceraldehyde
during light phase reducing power and assimilatory power are synthesized which are used in dark phase to reduce Co2 to carbohydrates
the dark phase comprises of initial carboxylation reaction, reduction of phosphoglyceric acid to phosphoglyceraldehyde and synthesis of carbohydrate and regeneration of ribulose 1,5 diphosphate from phosphoglyceraldehyde
How many type of photosynthetic cells occur in C4 plant is- a)One type
- b)Two type
- c)Four type
- d)Eight type
Correct answer is option 'B'. Can you explain this answer?
How many type of photosynthetic cells occur in C4 plant is
a)
One type
b)
Two type
c)
Four type
d)
Eight type
|
Kushagra Budhgaya answered |
C4 plants have 2 types of photosynthetic cells i.e. mesophyll and bundle sheath
Carbon refixation in C4 plants occurs in chloroplasts of :–
- a)Palisade tissue
- b)Spongy Mesophyll
- c)Bundle sheath cells
- d)Gaurd cells
Correct answer is option 'C'. Can you explain this answer?
Carbon refixation in C4 plants occurs in chloroplasts of :–
a)
Palisade tissue
b)
Spongy Mesophyll
c)
Bundle sheath cells
d)
Gaurd cells
|
Ved Patidar answered |
Carbon refixation(calvin cycle/final carbon fixation) in C4 plant occure in bundle sheath cells.
Bundle sheath chloroplast of C4 plant are :–[KCET–2003]- a)Large & agranal
- b)Large & granal
- c)Small & agranal
- d)Small & granal
Correct answer is option 'A'. Can you explain this answer?
Bundle sheath chloroplast of C4 plant are :–
[KCET–2003]
a)
Large & agranal
b)
Large & granal
c)
Small & agranal
d)
Small & granal
|
|
Prudhvi Learner answered |
AGRANAL BECAUSE IF GRANA PRESENT IT UNDERGOES LIGHT REACTION AND PHOTOLYSIS OF WATER AND OXYGEN IS RELEASED WHICH IS MAJOR PROBLEM
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Biology for JAMB
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