Question

Explain the phenomenon of photorespiration, why it is thought to occur (evolutionarily speaking), and why plants have evolved to minimize its occurrence.

Answer 1

Photorespiration or oxidative photosynthetic carbon cycle or C2 photosynthesis is a process in which enzyme RuBisCO oxygenates RuBP that leads to wastage of some energy formed during photosynthesis. This process involves three organelles chloroplast, peroxisomes and mitochondria.

Photorespiration occurs in dry and hot climatic plants when there is more oxygen in atmosphere than carbon dioxide. It is a light dependent process where glycolate is synthesized.

The plants have minimized its occurrence because it is a wasteful process. In photosynthesis carbon dioxide is used while in photorespiration carbon dioxide is releases. Thus, these processes work against each other so the plants minimize its occurrence.