FACTORS AFFECTING PHOTOSYNTHESIS – NCERT- NEET

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Factor	Description
Light Quality	Photosynthesis primarily uses red (650-700 nm) and blue (400-500 nm) light wavelengths, affecting the efficiency of photosynthesis.
Light Intensity	The rate of CO₂ fixation increases with light intensity up to a point. Beyond this point, chlorophyll can degrade, reducing photosynthesis.
Saturation Point (Light Intensity)	Shade-loving plants reach light saturation at around 10% of full sunlight, while sun-loving plants may require up to 50% of full sunlight.
Compensation Point (Light Intensity)	The point at which the rate of photosynthesis equals the rate of respiration; below this point, the plant cannot survive.
Carbon Dioxide Concentration	CO₂ is a major limiting factor. Increased CO₂ concentrations enhance photosynthesis until saturation is reached.
Saturation Point (CO₂ Concentration)	C₃ plants show saturation beyond 450 µl/L (approximately 500 ppm), while C₄ plants saturate around 360 µl/L.
Compensation Point (CO₂ Concentration)	The compensation point for CO₂ occurs at low concentrations, below which the plant cannot photosynthesize efficiently.
Temperature	Optimal temperature ranges differ among plant types. C₄ plants generally have a higher temperature optimum than C₃ plants.
Water Availability	Water is essential for photosynthesis; however, water stress causes stomatal closure, leading to reduced CO₂ uptake.
Chlorophyll Destruction	Excessive light intensity can lead to photooxidation, resulting in the breakdown of chlorophyll, thereby reducing photosynthetic efficiency.
Photosynthesis/Respiration (P/R) Ratio	The P/R ratio indicates the balance between photosynthesis and respiration. In optimal conditions, the ratio is greater than 1, while in stressful conditions, it may drop below 1.
Law of Limiting Factors	The rate of photosynthesis is determined by the most limiting factor; if one factor is insufficient, it restricts the overall process.