Here Krebs cycle and electron transport chain are topics of higher class
Glycolysis: The breakdown of glucose by enzymes, releasing energy and pyruvic acid.
Krebs cycle:the sequence of reactions by which most living cells generate energy during the process of aerobic respiration. It takes place in the mitochondria, using up oxygen and producing carbon dioxide and water as waste products, and ADP is converted to energy-rich ATP.
Electron transport chain:Electron transport chain is a series of reactions in which electrons are passed from one carrier to another, and finally to oxygen, resulting in the formation of water as well as NADH and FADH2 are oxidized to release the energy stored in them.