B1.4.3 - Factors Affecting the Rate of Photosynthesis

Light Intensity

Energy source for photosynthesis; affects rate.

Low Light Intensity

Limits energy, slowing photosynthesis rate.

High Light Intensity

Increases energy, enhances photosynthesis rate.

Light Intensity Plateau

Rate levels off after optimal intensity.

Carbon Dioxide Concentration

Key reactant; higher concentration boosts photosynthesis.

Low CO₂ Concentration

Limits photosynthesis due to insufficient reactant.

High CO₂ Concentration

Increases photosynthesis rate until maximum limit.

CO₂ Concentration Plateau

Rate levels off after reaching maximum concentration.

Temperature

Affects enzyme activity; crucial for photosynthesis.

Low Temperature

Reduces enzyme activity, slowing photosynthesis.

Optimum Temperature

Ideal temperature for maximum enzyme efficiency.

High Temperature

Can denature enzymes, reducing photosynthesis rate.

Temperature Graph

Shows rise, peak, then drop in photosynthesis rate.

Chlorophyll Concentration

Pigment that absorbs light; essential for photosynthesis.

Low Chlorophyll Concentration

Reduces light absorption, slowing photosynthesis.

High Chlorophyll Concentration

Increases light absorption, enhancing photosynthesis.

Water Availability

Essential reactant; affects structural integrity of plants.

Low Water Availability

Closes stomata, limiting CO₂ intake and photosynthesis.

Adequate Water

Maintains normal photosynthetic rates in plants.

Limiting Factors

Conditions that restrict maximum photosynthesis rate.

Interaction of Factors

Combined effects determine overall photosynthesis rate.

Key Takeaways

Light, CO₂, and temperature are main affecting factors.

Experimental Limiting Factor

Changing one factor reveals its limiting effect.