Photorespiration is a Wasteful process Justify

Photorespiration is considered a wasteful process for the following reasons – 

• It inhibits photosynthesis by diverting RuBisCO activity away from carbon fixation.
• It decreases the production of glucose and oxygen, which are important products of photosynthesis.
• It consumes ATP instead of producing it, resulting in a loss of energy for the plant.
• It leads to a loss of fixed carbon through the release of carbon dioxide.

Detailed Justification – “Photorespiration is a wasteful process”

Inhibition of Photosynthesis

• Photorespiration occurs when the enzyme RuBisCO mistakenly takes up oxygen instead of carbon dioxide during the Calvin cycle of photosynthesis.
• This oxygenation reaction inhibits the normal process of photosynthesis by diverting the activity of RuBisCO from carbon fixation.
• As a result, the production of glucose and other organic compounds, which are important products of photosynthesis, is reduced.

Decrease in Photosynthetic Products

• Oxygenation of RuBisCO leads to a decrease in the production of glucose and oxygen, both of which are important products of photosynthesis.
• Glucose serves as a source of energy and as a building block for plant growth and development.
• Oxygen is released as a by-product of photosynthesis and is essential for the survival of organisms that depend on oxygen for respiration.

ATP Utilisation

• During photorespiration, ATP is consumed instead of being produced, making it an energy-consuming process.
• The breakdown of glucose during normal respiration produces ATP, the energy currency of cells.
• However, during photorespiration, ATP is consumed to release the carbon dioxide that is produced during the oxygenation reaction.
• This represents a wasteful utilisation of ATP that could have been used for other important cellular processes.

Also Check – Photorespiration: The Futile Cycle?

Loss of Fixed Carbon

• Photorespiration leads to the release of carbon dioxide instead of fixing it in organic compounds.
• The oxygenation reaction produces a toxic compound called phosphoglycolate, which is then converted to glycolate and other compounds during photorespiration.
• These reactions result in the loss of fixed carbon, reducing the efficiency of carbon dioxide utilisation and decreasing the net carbon gain of the plant.