Optimum Conditions for photosynthesis
1) High intensity of a certain wavelength
• A higher intensity of light means there is more energy it can provide
• Only certain wavelengths of light are used for photosynthesis
• The photosynthetic pigments (chlorophyll a, chlorophyll b, and carotene) only absorb the red and blue lights in sunlight
2) Temperature
• Photosynthesis requires the use of enzymes which have tolerance to temperature before they either become inactive or denature
• A temperature <10oC the enzymes become inactive • A temperature >45oC the enzymes becomes denatured
• At a higher temperature, the stomata will close reducing water loss however also means less carbon dioxide can enter the leaf and therefore photosynthesis is reduced
3) Carbon Dioxide at 0.04%
• Carbon dioxide makes up 0.04% of the atmosphere
• Increase this to 0.4% gives a higher rate of photosynthesis
• Increasing this to >0.4% however causes the stomata to close
4) Water
• Plants require a continuous water supply
• A lack of water will reduce photosynthesis as it is required in hydrolysis reactions
• Too much water reduces photosynthesis as the uptake of minerals cannot occur, which are required for the production of chlorophyll a
Increasing Plant growth
• Limiting Factors can be reduced in a greenhouse

Limiting Factor

Management in Greenhouse

Light

·         Sunlight is allowed to pass through the glass roofs/windows during the day.

·         During the night lights are used to continue photosynthesis

Temperature

·         Greenhouses can trap the heat energy from the sunlight which thus warms up the surrounding air

·         Heaters/cooler systems can ensure optimum temperature is always met

·         Air circulation can ensure that heat is distributed evenly

Carbon Dioxide Concentration

·         Carbon dioxide is added to the air through the combustion of organic molecules e.g. propane in a generator