Cellular respiration explained simply

In short: Cellular respiration is the process by which cells gain energy in the form of ATP from glucose and oxygen. Carbon dioxide and water are produced as by-products.

In more detail: The process occurs in several steps, mainly in the cell’s mitochondria.

In detail

• Glycolysis: In the cytoplasm, glucose is broken down into two pyruvate molecules, already yielding some energy.
• Citric acid cycle: In the mitochondria, pyruvate is further broken down, loading electron carriers.
• Electron transport chain: The collected electrons drive a chain of proteins that build up a proton gradient.
• ATP synthesis: The proton gradient drives an enzyme that produces energy-rich ATP from ADP.
• Oxygen requirement: Efficient cellular respiration cannot occur without oxygen, which is why cells depend on a continuous oxygen supply.
• Anaerobic alternative: Without oxygen, cells fall back on less efficient fermentation processes, such as lactic acid fermentation in muscles.
• Energy yield: Full cellular respiration provides significantly more energy per glucose molecule than anaerobic processes (zelle-aufbau-und-funktion, enzyme-grundlagen).