Light is rarely a limiting factor for photosynsis, but excess amount of light reaching photosyntic parts of plant causes breakdown of chlorophyll and hence, reduces rate of photosynsis.

The most crucial step of Calvin cycle is carboxylation, where carbon dioxide is fixated into a stable organic intermediate. This organic intermediate is RuBP or ribulose bisphosphate.

The productivity of C₄ plants better than that of C₃ plants as C₄ plants lack photorespiration. C₄ plants do not show phosphoglycerate and phosphoglycolate formation, unlike C₃ plants.

Regeneration is third and final step of Calvin cycle. In this step, CO₂ acceptor molecule RuBP is regenerated. Regeneration requires 1 ATP molecule for purpose of phosphorylation.

When re is a water stress, its effects can be seen on plant. Water stress closes stomata hence carbon dioxide availability reduces. The leaves wilt to reduce surface area and metabolism.

The Calvin pathway occurs in C₃ plants in mesophyll cells. In such plants, first stable product of carbon dioxide fixation is 3-PGA or 3-phosphoglyceric acid. In C₄ plants, Calvin cycle occurs in bundle sheath cells.

Four electrons and four protons are produced at end of photolysis of water. Two molecules of water get converted into 4H⁺ and 4e^– along with free oxygen. The ions used for this splitting is Mn²⁺, Ca²⁺, and Cl^–.

C₄ plants have a special type of anatomy of leaves. This is known as Kranz anatomy. It is characterized by presence of large cells around vascular bundles in form of a wreath.

The process of photosynsis has two stages- light reaction and dark reaction. The products of light reaction are oxygen, ATP and NADPH. Oxygen diffuses out of chloroplast.

For every carbon dioxide molecule used up in Calvin cycle, 3 molecules of ATP are required. Hence, 3 molecules of ADP are produced. For six Calvin cycles, 18 molecules of ADP are produced.