10 Differences between Calvin Cycle and Krebs Cycle (C3 Cycle vs Citric Acid Cycle)

Difference between C3 cycle and citric acid cycle (Calvin cycle and Krebs cycle)

We have already discussed the difference between C3 and C4 cycle, C3, C4 and CAM cycle. In this post we are discussing the difference between Calvin Cycle or C3 cycle in Photosynthesis and Krebs cycle in Cellular Respiration

Calvin Cycle or C3 cycle	Krebs Cycle or Citric Acid Cycle
A stage in photosynthesis where CO2 is fixed to carbohydrate using energy (ATP and NADPH) produced during light reaction	A stage in cellular respiration that involves series of reactions that produces carbon dioxide molecules, GTP/ATP and reduced forms of NADH and FADH2.
An anabolic process where carbohydrate is synthesized	An catabolic process where respiratory substrates such as carbohydrates, fats etc are broken down releasing energy
Site of reaction is stroma of chloroplast	Site of reaction is matrix of mitochondrion
Occur in plants	Takes place in all aerobic organisms including plants
Anaerobic process (oxygen not involved)	Aerobic process that involves oxygen in Electron transport chain which is essential for running Krebs cycle
Produces glucose using energy	Oxidizes glucose releasing energy
The first stable compound is 3 carbon phosphoglyceric acid	The first stable compound is 6 carbon Citric acid
RuBisCO is the first enzyme of the Calvin cycle	Citrate synthase is the first enzyme of the citric acid cycle
ATP and CO2 used in the cycle	ATP and CO2 produced in the cycle
Carbohydrate is synthesized	1 GTP/ATP, 3 NADH + H+, 1FADH2 & 2 carbon dioxide molecule per turn of cycle