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  2. Electron transport chain - Wikipedia

    en.wikipedia.org/wiki/Electron_transport_chain

    Appearance. hide. An electron transport chain (ETC[ 1 ]) is a series of protein complexes and other molecules which transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this electron transfer with the transfer of protons (H + ions) across a membrane.

  3. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Oxygen is a chemical element; it has symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the most abundant element in Earth's crust, and after hydrogen and helium, it ...

  4. Passive transport - Wikipedia

    en.wikipedia.org/wiki/Passive_transport

    Passive diffusion across a cell membrane.. Passive transport is a type of membrane transport that does not require energy to move substances across cell membranes. [1] [2] Instead of using cellular energy, like active transport, [3] passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes.

  5. Oxidative phosphorylation - Wikipedia

    en.wikipedia.org/wiki/Oxidative_phosphorylation

    Oxidative phosphorylation is made up of two closely connected components: the electron transport chain and chemiosmosis. The electron transport chain in the cell is the site of oxidative phosphorylation. The NADH and succinate generated in the citric acid cycle are oxidized, releasing the energy of O 2 to power the ATP synthase.

  6. Anaerobic respiration - Wikipedia

    en.wikipedia.org/wiki/Anaerobic_respiration

    Anaerobic respiration is respiration using electron acceptors other than molecular oxygen (O 2). Although oxygen is not the final electron acceptor, the process still uses a respiratory electron transport chain. [1] In aerobic organisms undergoing respiration, electrons are shuttled to an electron transport chain, and the final electron ...

  7. Facilitated diffusion - Wikipedia

    en.wikipedia.org/wiki/Facilitated_diffusion

    Facilitated diffusion in cell membrane, showing ion channels and carrier proteins. Facilitated diffusion (also known as facilitated transport or passive-mediated transport) is the process of spontaneous passive transport (as opposed to active transport) of molecules or ions across a biological membrane via specific transmembrane integral proteins. [1]

  8. Human iron metabolism - Wikipedia

    en.wikipedia.org/wiki/Human_iron_metabolism

    The human body needs iron for oxygen transport. Oxygen (O 2) is required for the functioning and survival of nearly all cell types. Oxygen is transported from the lungs to the rest of the body bound to the heme group of hemoglobin in red blood cells. In muscles cells, iron binds oxygen to myoglobin, which regulates its release.

  9. Respiration (physiology) - Wikipedia

    en.wikipedia.org/wiki/Respiration_(physiology)

    Ventilation refers to the in-and-out movement of air of the lungs and perfusion is the circulation of blood in the pulmonary capillaries. [1] In mammals, physiological respiration involves respiratory cycles of inhaled and exhaled breaths. Inhalation (breathing in) is usually an active movement that brings air into the lungs where the process ...