Factors Affecting Photosynthesis, Such as the PH

Photosynthesis is a chemical reaction that helps plants convert carbon-dioxide and water into oxygen and food, with chlorophyll and sunlight acting as catalysts. Many factors affect the rate of photosynthesis. An increase or decrease in those levels affect photosynthesis.

Major Factors

• The major factors affecting photosynthesis are light, carbon concentration, temperature, chlorophyll and water. Any changes to these levels affect photosynthesis. The optimum levels of these factors bring about the best photosynthesis rates. This knowledge is frequently used to increase crop yield in greenhouses.

pH Balance

• One of the other factors affecting photosynthesis is the pH balance. pH is the measurement of alkalinity or acidity of a solution. A pH of 7 is neutral. A pH below 7 indicates an acidic nature; above 7 indicates alkaline nature.

  The pH levels have an affect on carbon transport during photosynthesis. A research study by William A. Dodd II and R.G.S. Bidwell from the Department of Biology, Queen's University, Kingston, Canada, has shown that pH balances affect the flow of carbon to the various photosynthetic intermediates. Some of the photosynthetic intermediates affected by pH balance are glycine, sucrose, glycolate and serine.

  At higher pH levels a higher amount of carbon entered the intermediate pathways. pH levels of 7.6 and 7.7 were found to be optimum levels at which maximum rate of photosynthesis was observed. At higher pH ranges it was found that the carbon levels in intermediates were pretty much the same as chloroplast levels.

Levels of Oxygen

• A similar study at Research School of Biological Sciences, Australian National University, studied the affect of pH along with oxygen on photosynthetic reactions. An increase or decrease in the levels of oxygen did not make much difference to the process of photosynthesis when carbon-dioxide levels were at saturation point. But it was observed that the presence of oxygen inhibited photosynthesis, when there was increase in pH levels.

  The pH value was increased to reach 8 with the addition of bicarbonate. It was observed that oxygen evolution during photosynthesis was affected by a fall of 30%. This was aided by the presence of non-photosynthetic oxygen. An increased oxygen concentration led to decreased oxygen evolution during photosynthesis. Similar experiments with an acid base showed that the Adenosine tri-phosphate (ATP) levels were not affected by oxygen.

  A study in Scotland studied the affect pH levels in aquatic plant photosynthesis. It was observed that extremely low pH levels affected the photosynthetic levels of the aquatic plants. The rate of photosynthesis dropped drastically at pH limits of 1.5 and below.