Apoorva Arora
Last Activity: 10 Years ago
Photorespiration(also known as theoxidative photosynthetic carbon cycle, orC2 photosynthesis) is a process inplant metabolismwhich attempts to ameliorate the consequences of a wasteful oxygenation reaction by theenzymeRuBisCO. The desired reaction is the addition ofcarbon dioxidetoRuBP(carboxylation), a key step in theCalvin-Benson cycle, however approximately 25% of reactions byRuBisCOinstead add oxygen to RuBP (oxygenation), producing a product that cannot be used within the Calvin-Benson cycle. This process reduces efficiency of photosynthesis, potentially reducing photosynthetic output by 25% inC3plants. Photorespiration involves a complex network of enzyme reactions that exchange metabolites betweenchloroplasts, leafperoxisomesand mitochondria.
So th correct option is 4.