| biological transport | The movement of materials (including biochemical substances and drugs) across cell membranes and epithelial layers, usually by passive diffusion. (12 Dec 1998) |
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| biological transport, active | The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy. (12 Dec 1998) |
| vectorial transport | <physiology> Transport of an ion or molecule across an epithelium in a certain direction (e.g. absorption of glucose by the gut). Vectorial transport implies a nonuniform distribution of transport proteins on the plasma membranes of two faces of the epithelium. (06 Mar 2000) |
| paracellular transport | Solvent movement across an epithelial cell layer through the tight junctions between cells. Compare: transcellular transport. (05 Mar 2000) |
| vesicular transport | <cell biology> Process of transport of material across an epithelium by uptake on one face into a coated vesicle, which may then be sorted through the trans Golgi network and transported to the opposite face in another set of vesicles. (17 Mar 1998) |
| passive transport | <biochemistry, physiology> The movement of a substance, usually across a plasma membrane, by a mechanism that does not require metabolic energy. See: active transport, transport protein, facilitated diffusion, ion channels. (18 Nov 1997) |
| respiratory transport | The processes of gas exchange and various metabolic functions taking place in the lung, generally at the alveolar level. (12 Dec 1998) |
| membrane transport | <cell biology> The transfer of a substance from one side of a plasma membrane to the other, in a specific direction and at a rate faster than diffusion alone. See: active transport. (18 Nov 1997) |
| retrograde axonal transport | <cell biology> The transport of vesicles from the synaptic region of an axon towards the cell body: involves the interaction of MAP1C with microtubules. (11 Jan 1998) |
| channel transport | <radiobiology> In inertial fusion research using light ion drivers, describes the use of current-carrying plasma channels (which are magnetically confined to the channel) to transport electron or ion beams between the ion diode and the fusion target. This allows the ion source to stand back from the target. (09 Oct 1997) |
| reverse electron transport | <chemistry> The energy-dependent movement of electrons against the thermodynamic gradient to form a strong reductant from a weaker electron donor. (11 Jan 1998) |
| cholesterol ester transport proteins | A protein that transports cholesterol esters from HDL to VLDL and LDL; a deficiency of this protein is associated with elevated HDL cholesterol. (05 Mar 2000) |
| monosaccharide transport proteins | Membrane transport proteins which bind glucose and sodium ions and enter the cell together. The sodium ions are then pumped out of the cell by a sodium potassium atpase. The rate and extent of the sugar transport depends on the sodium ion concentration. Inhibitors of the monosaccharide transport system are phlorizin, cytochalasin b, and inhibitors of the sodium potassium atpase system. Insulin increases the rate of monosaccharide transport across the membrane into the cell. (12 Dec 1998) |
| cotranslational transport | <cell biology> Process whereby a protein is moved across a membrane as it is being synthesised. This process occurs during the translation of the message at membrane associated ribosomes in rough endoplasmic reticulum during the synthesis of secreted proteins in eukaryotic cells. (18 Nov 1997) |
| coupled transport | The linked, simultaneous transport of two substances across a cell membrane (or another intracellular membrane). If the two substances are moving in the same direction (both into the cell or both out of the cell) it is called symport. If the two substances are moving in opposite directions (one moves into the cell while the other moves out) it is called antiport. (09 Oct 1997) |