What is the consequence of insufficient carbon dioxide on photosynthesis?

When carbon dioxide levels are insufficient, the process of photosynthesis is hindered, which can lead to a shift in the behavior of the enzyme Rubisco. Rubisco normally catalyzes the reaction of carbon dioxide with ribulose bisphosphate to initiate the Calvin cycle, which ultimately leads to the synthesis of glucose. However, when there isn’t enough carbon dioxide available, Rubisco can begin to bind with oxygen instead, a process known as photorespiration. This reaction not only decreases the efficiency of photosynthesis but can also lead to a decrease in plant productivity.

By binding with oxygen, Rubisco creates a molecule that is ultimately less useful for the plant in terms of energy storage compared to the product generated when it binds with carbon dioxide. Thus, insufficient carbon dioxide not only negatively impacts photosynthesis but also results in increased oxygen binding, which can be detrimental to the plant's energy capture and overall health.