Photorespiration does what?

[doc3232]

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So it basically rubisco binds with O2 to form something useless then peroxisomes use energy to reform the rubisco?

Also, wouldn't C4 be somewhat ineffective because while the stomata are closed during the day wouldn't O2 build up in the cell from all the light-dependent reactions???

THANKS 🙂

 

[funktion]

In photorespiration, oxygen binds to rubisco forming 1 molecule of 3-phosphoglycerate and 1 molecule of 2-phosphoglycolate. Normally, when rubisco binds CO2, 2 molecules of 3-phosphoglycerate are formed which then are used in calvin cycle. photorespiration forms less 3-phosphoglycerate and produces the 2-phosphoglycolate which is toxic and the plant has to expend energy to remove it.

For your question about C4 plants, these plants do not temporally separate carbon assimilation like CAM plants but spatially separate it. C4 have their stomata open during the day and utilize a unique enzyme that has greater affinity for CO2 and transport carbon away from leaf surface which is exposed to high atmospheric oxygen levels to fix carbon and reduce photorespiration.

 

[doc3232]

Thanks, got it.
PEP carboxylase is that enzyme right? The one that has a higher affinity for CO2.
Do C4 plants have rubisco in the mesophyll leaves?