Advertisements
Advertisements
प्रश्न
RuBisCo is an enzyme that acts both as a carboxylase and oxygenase. Why do you think RuBisCo carries out more carboxylation in C4 plants?
उत्तर
- RuBisCO is an enzyme that functions as an oxygenase (during photorespiration) and carboxylase (during photosynthesis). However, in C4 plants, RuBisCO performs greater carboxylation. Mesophyll cells in C4 plants are where carbon dioxide is first fixed.
- Phosphoenol pyruvate, or PER, is the main absorber of carbon dioxide. When PEP carboxylase or PEP case, is present, it reacts with carbon dioxide to produce oxaloacetic acid or oxaloacetate. Through plasmodesmata, malic or aspartic acid is translocated to bundle sheath cells.
- They undergo decarboxylation (or, in the case of aspartic acid, deamination) inside the bundle sheath cells to produce pyruvate and CO2. Through the Calvin cycle, CO2 is once again trapped inside the bundle sheath cells. In C4 plants, RuBP of the Calvin cycle is referred to as the secondary or ultimate acceptor of CO2. Pyruvate returns to the cells of the mesophyll
APPEARS IN
संबंधित प्रश्न
By looking at a plant externally can you tell whether a plant is C3 or C4? Why and how?
Give a comparison between the following:
C3 and C4 pathways
Give comparison between the following:
Anatomy of leaf in C3 and C4 plants
In the maize plant, \[\ce{CO2}\] fixation occurs in both mesophyll and bundle sheath cells. The enzymes involved in these cells for the process respectively are, ______.
In case of C4 pathway, the first step is
In C4-pathway initial carbon dioxide fixation occurs in chloroplasts of ______.
The first stable product of CO2 fixation in sorghum is ______.
The enzyme that is not found in a C3 plant is ______.
When CO2 is added to PEP, the first stable product synthesised is ______.
Some of these terms/chemicals are associated with the C4 cycle. Explain.
Bundle sheath cells
In what kind of plants do you come across ‘Kranz’ anatomy? To which conditions are those plants better adapted? How are these plants better adapted than the plants which lack this anatomy?
Observe the diagram and answer the following.
- Which group of plants exibits these two types of cells?
- What is the first product of C4 cycle?
- Which enzyme is there in bundle sheath cells and mesophyll cells?
A cyclic process is occurring in C3 plant, which is light dependent, and needs O2. This process doesn’t produce energy rather it consumes energy.
- Can you name the given process?
- Is it essential for survival?
- What are the end products of this process?
- Where does it occur?
What special anatomical features are displayed by leaves of C4 plants? How do they provide advantage over the structure of C3 plants?
Name the two important enzymes of C4 pathway, and explain their role in fixing CO2?
