EVERYDAY SCIENCE

Detailed explanation-1: -The first reaction of this pathway is oxygen fixing reaction, which produces 2 phoshpoglycolate and 3 phosphoglyceric acid. This reaction occurs in the chloroplast.

Detailed explanation-2: -Photorespiration is the process of light-dependent uptake of molecular oxygen (O2) concomitant with release of carbon dioxide (CO2) from organic compounds. The gas exchange resembles respiration and is the reverse of photosynthesis where CO2 is fixed and O2 released.

Detailed explanation-3: -Photorespiration is a process that occurs in Calvin Cycle during plant metabolism. In this process, the key enzyme RuBisCO that is responsible for The fixing of carbon dioxide reacts with oxygen rather than carbon dioxide.

Detailed explanation-4: -Oxygenation activity of RuBisCO produces one molecule of 3C compound PGA, and one molecule of 2C compound phosphoglycolate. During the carboxylation step of Calvin cycle, RuBP combines with CO2 to form 2 molecules of 3PGA (3C), which is catalysed by RuBisCO.

Detailed explanation-5: -During photorespiration, the oxygen consuming reactions occur in the stroma of chloroplasts and peroxisomes. In chloroplasts, RuBP (5 carbon compound) on receiving oxygen gets converted into PGA (3 carbon compound) and phosphoglycolate (2 carbon compound).