Cellular Respiration Pathway

Overview of Cellular Respiration

The diagram is a nice summary of the cellular respiration. There are 4 main stages in the cellular respiration. The first stage, Glycolysis, literally means splitting sugars. In the picture, 6-Carbon glucose molecule is converted to two 3-Carbon Pyruvate molecules. Energy of the glucose is released as ATP and high energy electrons of the glucose are transferred to NAD+ molecule. In the second stage Acetyl CoA molecules are produced as a result of the oxidative decarboxylation reaction. This reaction also releases carbondioxide molecules and transfers high energy electrons to NADH molecules. In the next stage, Krebs Cycle or Citric Acid Cycle, energy is produced in the form of ATP, CO2 molecules are released. NADH, FADH2 molecules formed in the first three stages of  cellular respiration are transferred to the ETC. Electron Transport Chain, removes high energy electrons from electron carriers and establishes proton gradient that is used to produce ATP.