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Electron Transport Chain definitions

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  • Electron Transport Chain
    A mitochondrial process involving sequential redox reactions that transfer electrons to generate a proton gradient for ATP synthesis.
  • Aerobic Respiration
    A metabolic pathway using oxygen to extract energy from nutrients, culminating in ATP production via the electron transport chain.
  • NADH
    A high-energy coenzyme produced in the citric acid cycle that donates electrons to the first complex of the electron transport chain.
  • FADH2
    A reduced coenzyme from the citric acid cycle that transfers electrons to the second complex of the electron transport chain.
  • Complex 1
    A protein assembly in the inner mitochondrial membrane that accepts electrons from NADH and pumps protons into the intermembrane space.
  • Complex 2
    A membrane-bound protein that receives electrons from FADH2 and passes them to Coenzyme Q without pumping protons.
  • Complex 3
    A mitochondrial protein complex that receives electrons from Coenzyme Q and pumps protons into the intermembrane space.
  • Complex 4
    The final protein complex in the chain, transferring electrons to oxygen and pumping protons to maintain the gradient.
  • Coenzyme Q
    A lipid-soluble electron carrier that shuttles electrons from Complexes 1 and 2 to Complex 3 within the inner mitochondrial membrane.
  • Cytochrome c
    A small, multifunctional protein that transports electrons between Complex 3 and Complex 4 in the electron transport chain.
  • Proton Gradient
    An electrochemical difference created by the accumulation of H+ ions in the intermembrane space, driving ATP synthesis.
  • Intermembrane Space
    The compartment between the inner and outer mitochondrial membranes where protons accumulate during electron transport.
  • Mitochondrial Matrix
    The innermost compartment of mitochondria where the citric acid cycle occurs and protons are drawn from during electron transport.
  • Oxygen
    The terminal electron acceptor in the chain, combining with electrons and protons to form water at the end of the process.
  • ATP
    The primary energy currency of the cell, synthesized using the energy stored in the proton gradient established by the electron transport chain.