Aerobic Metabolism Overview

Aerobic Metabolism Overview

• Aerobic metabolism is the primary source of ATP during low-intensity activities.
• It primarily uses carbohydrates and fats as substrates.
• The Krebs cycle's main function is generating electron carriers.
• These electron carriers are transported to the electron transport chain (ETC) to produce ATP.
• Over 90% of ATP is generated this way in the body.
• Necessary for endurance activities and exercise recovery.

Glycolysis to Krebs Cycle

• Glycolysis produces 2 pyruvate molecules.
• Pyruvate, entering the mitochondria, converts to Acetyl-CoA.
• Acetyl-CoA enters the Krebs cycle.
• NADH and FADH₂ enter the electron transport chain (ETC) to synthesize ATP (over 90%).

Oxidative (Aerobic) System

• The ETC takes electrons and hydrogen atoms from NADH and FADH₂ merging them with oxygen to create ATP.
• This hydrogen/electron flow powers ATP synthase to form ATP.

Krebs Cycle Details

• Amino acids are oxidized to form Pyruvate and CO₂.
• Fatty acids are oxidized via beta oxidation forming Acetyl-CoA.
• Acetyl-CoA enters the Krebs cycle.
• The cycle produces NADH, FADH₂, ATP, and CO₂ .
• Key enzymes include Isocitrate dehydrogenase and α-ketoglutarate dehydrogenase.

Electron Transport Chain (ETC)

• The ETC is a series of protein complexes located in the inner mitochondrial membrane.
• It receives NADH and FADH₂, which release electrons and hydrogen ions.
• This process generates a proton gradient (H⁺).
• The gradient drives ATP synthase.
• Oxygen accepts electrons and combines with hydrogen ions to form water (H₂O).
• Key components include NADH dehydrogenase, cytochrome bc1 complex, cytochrome c oxidase complex, and ATP synthase.