C3 and C4 Cycle: Differences in Process, Efficiency, and Adaptation
C3 and C4 cycles are two distinct photosynthetic pathways that plants use to capture carbon dioxide. The C3 cycle, or Calvin cycle, is the most common and works best under cooler, moist conditions. The C4 cycle, an adaptation found in certain plants, enhances efficiency in hot, dry, and high-light environments by minimizing photorespiration.
C3 vs. C4 Photosynthesis: Key Differences
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FAQs on Difference Between C3 and C4 Cycle
1. What is the major difference between C3 and C4 cycle?
The major difference is in their initial CO₂ fixation. C3 plants directly fix CO₂ through the Calvin cycle into a 3-carbon compound, while C4 plants first convert CO₂ into a 4-carbon compound, which helps minimize photorespiration.
2. Which of the following is a difference between C3 and C4 plants?
A key difference is that C4 plants have specialized bundle-sheath cells and a CO₂-concentrating mechanism, whereas C3 plants lack these adaptations.
3. What is the difference between C3 and C4 plants in photorespiration?
C3 plants are more prone to photorespiration, especially in high-temperature and high-oxygen environments, whereas C4 plants significantly reduce photorespiration through their specialized CO₂ concentration process.
4. What are the advantages of C4 cycle over C3 cycle?
The C4 cycle offers advantages such as improved efficiency under high light, high temperature, and drought conditions, along with reduced photorespiration and enhanced water use efficiency.
5. Is tomato a C3 or C4 plant?
Tomato is classified as a C3 plant, meaning it utilizes the Calvin cycle for CO₂ fixation. This process works best in cooler, moist environments but can be less efficient in extremely hot conditions.
6. What are the major differences between C3, C4, and CAM plants?
C3 plants: Use the Calvin cycle for CO₂ fixation into a 3-carbon compound.
C4 plants: Initially fix CO₂ into a 4-carbon compound using a specialized structure (bundle-sheath cells) to reduce photorespiration.
CAM plants: Fix CO₂ at night to reduce water loss, storing it as malate for use during the day.
7. Is rice C3 or C4?
Rice is a C3 plant, primarily relying on the Calvin cycle for its photosynthetic process. This pathway is more efficient in the cooler, wetter conditions typical of rice-growing regions.
8. What is C3 and C4?
They refer to two different photosynthetic pathways. C3 plants fix CO₂ directly into a 3-carbon compound via the Calvin cycle, while C4 plants incorporate an additional CO₂ concentration step by first forming a 4-carbon compound.
9. What is the C4 cycle?
The C4 cycle is a photosynthetic mechanism where CO₂ is first fixed into a 4-carbon compound in mesophyll cells, then transported to bundle-sheath cells for the Calvin cycle, effectively reducing photorespiration.
10. What is the full form of CAM plant?
CAM stands for Crassulacean Acid Metabolism. This adaptation allows plants to open their stomata at night to fix CO₂, minimizing water loss during the heat of the day while storing carbon for daytime photosynthesis.
