Photosynthesis, the process by which plants create their food, can be affected by changes in pH within the leaves. PH is the measure of the acidity of a solution, and it can have a large effect on many biological processes.
The PH Scale
The pH scale ranges from 0 to 14, with 7 being neutral. Measurements below 7 indicate acidity, and measurements above 7 indicate that a solution is alkaline, or basic.
PH and Biological Processes
Changes in pH affect all biological processes, primarily through its influence on enzymes. Enzymes are important \"workers\" inside cells that are disabled by extremes in pH.
The Optimum PH for Photosynthetic Enzymes
RuBisCO is the key carbon-fixing enzyme in the process of photosynthesis, and it functions optimally at a pH of 8.
The Effect of Raising or Lowering the PH
Raising or lowering the pH from 8 will negatively influence the rate of photosynthesis because RuBisCO will begin to work more slowly. When the pH reaches 6 on the low side and 10 on the high side, RuBisCO will cease working altogether.
Besides RuBisCO, there are many enzymes and proteins involved in the photosynthetic process; all of them are negatively affected by the raising or lowering of pH from the optimal level.