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  2. 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.

  3. Uniporter - Wikipedia

    en.wikipedia.org/wiki/Uniporter

    Facilitated diffusion may occur through three mechanisms: uniport, symport, or antiport. The difference between each mechanism depends on the direction of transport, in which uniport is the only transport not coupled to the transport of another solute. [4] Uniporter carrier proteins work by binding to one molecule or substrate at a time ...

  4. Membrane transport - Wikipedia

    en.wikipedia.org/wiki/Membrane_transport

    As mentioned above, passive diffusion is a spontaneous phenomenon that increases the entropy of a system and decreases the free energy. [5] The transport process is influenced by the characteristics of the transport substance and the nature of the bilayer. The diffusion velocity of a pure phospholipid membrane will depend on: concentration ...

  5. 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]

  6. Membrane transport protein - Wikipedia

    en.wikipedia.org/wiki/Membrane_transport_protein

    Osmosis is the passive diffusion of water across a cell membrane from an area of high concentration to an area of low concentration. Since Osmosis is a passive process, like facilitated diffusion and simple diffusion, it does not require the use of ATP.

  7. Transcellular transport - Wikipedia

    en.wikipedia.org/wiki/Transcellular_transport

    There are two types of passive transport, passive diffusion and facilitated diffusion. Passive diffusion is the unassisted movement of molecules from high concentration to low concentration across a permeable membrane. [2] One example of passive diffusion is the gas exchange that occurs between the oxygen in the blood and the carbon dioxide ...

  8. Electrochemical gradient - Wikipedia

    en.wikipedia.org/wiki/Electrochemical_gradient

    Since the ions are charged, they cannot pass through cellular membranes via simple diffusion. Two different mechanisms can transport the ions across the membrane: active or passive transport. [citation needed] An example of active transport of ions is the Na +-K +-ATPase (NKA).

  9. Gas exchange - Wikipedia

    en.wikipedia.org/wiki/Gas_exchange

    The exchange of gases occurs as a result of diffusion down a concentration gradient. Gas molecules move from a region in which they are at high concentration to one in which they are at low concentration. Diffusion is a passive process, meaning that no energy is required to power the transport, and it follows Fick's law: [citation needed]