The present work studies the effects of cold on photosynthesis, as well as the involvement in the chilling stress of chlororespiratory enzymes and ferredoxin-mediated cyclic electron flow, in illuminated plants of Hibiscus rosa-sinensis.Plants were sensitive to cold stress, as indicated by a reduction in the photochemistry efficiency of PSII and in the capacity for electron transport. As mentioned above, it is clear the field of ‘quantum effects in biology’ is the most well tested in photosynthesis—where quantum processes have been directly observed. The effect of diffusional and photochemical limitations to photosynthesis was assessed in field-grown water-stressed grapevines (Vitis vinifera L.) by combined measurements of gas exchange and chlorophyll fluorescence.

It is suggested that C 4 plants have photorespiration and high O 2 stimulates it. Plot of the dissolved oxygen probe output during the last 5 minutes of a 20 minute incubation of a Posidonia sinuosa plant at a temperature of 23 oc and light intensity of 1020 J..UDOl m-2s-1

Structures of photosynthetic apparatus provide more reliable information on the relevant states involved.

The experimental apparatus used to determine the effects of light and temperature on photosynthesis. The main variables which affect photosynthesis are light, water, CO 2 concentration and temperature.. On a deeper level, other factors like amount of chlorophyll, availability of nutrients (eg Mg is needed for chlorophyll synthesis) will also affect the rate of photosynthesis, though these are rarely covered in discussion of this topic.

What factor most affects the rate of photosynthesis?

The rate of photosynthesis increases by 30-50% when the concentration of oxygen in air is reduced from 20% to 0.5% and CO 2, light and temperature are not the limiting factors.

Oxygen has been shown to inhibit photosynthesis in C 3 plants while C 4 plants show little effect.

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities.