Question

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

Answer 1

In the case of C₃ pathways, carbon is fixed into a 3-carbon compound, i.e. 3-PGA. On the other hand, in the case of C₄ pathways, carbon is fixed into a 4-carbon compound, i.e. oxaloacetic acid. Thus, the amount of carbon atoms in the end product is the purpose for establishing the C₃ and C₄ pathways of photosynthesis.