Ncert Exercises & Solutions

What is the basis for designating C₃ and C₄ pathways of photosynthesis?

The basis for designating C₃ and C₄ pathways of photosynthesis is as follows

C₃Pathway	C₄ Pathway
In Calvin cycle or C₃ cycle (dark reaction), carbon dioxide is fixed into first stable compound called 3-PGA,(3 phorphoglyceric acid) which is a 3 carbon compund.	In C₄ plants, the Calvin cycle C₃ cycle occurs in bundle sheath cells. Prior to reaching there, the CO₂ is trapped by mesophyll cells and fixed into a 4-carbon stable product called oxalo acetic acid.