Effects of Temperature on Photosynthesis

Photosynthesis is the earth’s most incredible biochemical processes that enable plant to manufacture glucose in presence of sunlight, carbon (IV) oxide and water. Science has proved that the photosynthesis rate directly depends on variables such light intensity, temperature and ph. The process takes-place in the chloroplast found in the leave’s cells. An optimum rate of photosynthesis attracts production of larger amounts of CO2 leading to production of larger amounts of glucose. The CO2 assimilation is the best indicator of the photosynthetic rate, since it shows notable variation with changes in temperature. Using this process, scientists categorise the effects of temperature on photosynthesis into three categories.

The first is the low temperatures stage, which lies between 0 to 10 degrees Celsius. Living organism use enzymes, which are characterized by their protein nature, to carry out their biochemical reaction processes. The proteins fold into defined forms that enable them to bind well to the molecules of interests. Here, the enzymes that catalyse photosynthetic rate work inefficiently, decreasing the rate of photosynthesis. This reduces the rate of glucose production in plants leading to stunted growth.

The second stage is medium temperatures also known as optimum temperatures that vary from 10-20 degree Celsius. Under this condition, photosynthetic enzymes are functioning in a favourable environment leading to optimum photosynthetic rate. In this stage, the only limiting factor is the diffusion of CO2 into the leaves.

Last is the stage of high temperatures that are above 20 degrees Celsius. Here, photosynthetic rate decreases with an increase in temperatures because this condition is unfavourable for enzymes to work efficiently. The situation cannot be restored even with an increase in diffusion of CO2 into the leaves. Eventually, at temperatures above 40 degrees Celsius, the photosynthetic enzymes lose their functionality, shape and die causing photosynthesis to decline suddenly.

However, in the photochemical reaction, photosynthesis is independent of temperatures. If CO2 and light intensity remain constant, the photosynthetic rate increases with as increase in temperatures. In majority of plants, photosynthesis can occur under minimum temperatures of 0 degrees Celsius. However, the photosynthetic rate is very minimal, and doubles with each increase of 10 degrees Celsius up to optimal temperatures. Beyond the optimal temperatures, photosynthetic rate begins to decrease until it ceases. Most plants have experience an optimal photosynthetic rate at approximately 25 degrees Celsius. Lower temperatures below 0 degree Celsius can also make the enzymes inactive to catalyse the photosynthetic rate.