What occurs in the photorespiratory pathway?

Step-by-step solution

Let us try and understand one more process that creates an important difference between C3 and C4 plants – Photorespiration. To understand photorespiration we have to know a little bit more about the first step of the Calvin pathway – the first CO2 fixation step. This is the reaction where RuBP combines with CO2 to form 2 molecules of 3PGA, that is catalysed by RuBisCO. In C3 plants some O2 does bind to RuBisCO, and hence CO2 fixation is decreased. Here the RuBP instead of being converted to 2 molecules of PGA bind