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  2. Osmosis - Wikipedia

    en.wikipedia.org/wiki/Osmosis

    The process of osmosis over a semipermeable membrane.The blue dots represent particles driving the osmotic gradient. Osmosis (/ ɒ z ˈ m oʊ s ɪ s /, US also / ɒ s-/) [1] is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential ...

  3. Semipermeable membrane - Wikipedia

    en.wikipedia.org/wiki/Semipermeable_membrane

    Semipermeable membrane is a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure , concentration , and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute.

  4. Membrane transport - Wikipedia

    en.wikipedia.org/wiki/Membrane_transport

    In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. The regulation of passage through the membrane is due to selective membrane permeability – a ...

  5. Chemiosmosis - Wikipedia

    en.wikipedia.org/wiki/Chemiosmosis

    Chemiosmosis is the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient.An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H +) across a membrane during cellular respiration or photosynthesis.

  6. Membrane transport protein - Wikipedia

    en.wikipedia.org/wiki/Membrane_transport_protein

    Facilitated diffusion in the cell membrane, showing ion channels (left) and carrier proteins (three on the right). Facilitated diffusion is the passage of molecules or ions across a biological membrane through specific transport proteins and requires no energy input. Facilitated diffusion is used especially in the case of large polar molecules ...

  7. Molecular diffusion - Wikipedia

    en.wikipedia.org/wiki/Molecular_diffusion

    In cell biology, diffusion is a main form of transport for necessary materials such as amino acids within cells. [1] Diffusion of solvents, such as water, through a semipermeable membrane is classified as osmosis. Metabolism and respiration rely in part upon diffusion in addition to bulk or active processes.

  8. 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.

  9. Electrochemical gradient - Wikipedia

    en.wikipedia.org/wiki/Electrochemical_gradient

    Diagram of ion concentrations and charge across a semi-permeable cellular membrane. An electrochemical gradient is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts: The chemical gradient, or difference in solute concentration across a membrane.