What is photorespiration?

1 Answer
Write your answer here...
Start with a one sentence answer
Then teach the underlying concepts
Don't copy without citing sources


Write a one sentence answer...



Explain in detail...


I want someone to double check my answer

Describe your changes (optional) 200

Jun 9, 2017


Photorespiration involves a complex network of enzyme reactions that exchange metabolites between chloroplasts, leaf peroxisomes and mitochondria.


It refers to a process in plant metabolism where the enzyme RuBisCo oxygenates RuBP, causing some of the energy produced by photosynthesis to be wasted. Photorespiration occurs when the carbon dioxide levels inside a leaf become low. This happens on hot dry days when a plant and s forced to close its stomata to prevent excess water loss.

Photorespiration may be necessary for the assimilation of nitrate from the soil. The photorespiration pathway influences a wide range of processes from bioenergetics, Photosystem II functions, and carbon metabolism to nitrogen assimilation and respiration.

It is also a major source of hydrogen peroxide in photosynthetic cells. Through hydrogen peroxide production and pyridine nucleotide interactions , photorespiration makes a key contribution to cellular redox homeostasis. In doing so it influences multiple signalling pathways, in particular, those that govern plant hormonal responses controlling growth, environmental and defense responses, and programmed cell deaths.

Although photorespiration is greatly reduced in C4 species, it is still an essential pathway.

Was this helpful? Let the contributor know!
Impact of this question
63 views around the world
You can reuse this answer
Creative Commons License