Biological Transport
| Definition: |
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments. |
| Notes: |
almost never IM; coord NIM with endogenous substance /metab (IM) or exogenous substance /pharmacokin (IM); DF: BIOL TRANSPORT |
Biological Transport Categories.
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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. |
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Capillary Permeability - The property of blood capillary vessels ENDOTHELIUM that allows for the selective exchange of substances between the blood and surrounding tissues and through membranous barriers such as the BLOOD-AIR BARRIER; BLOOD-AQUEOUS BARRIER; BLOOD-BRAIN BARRIER; BLOOD-RETINAL BARRIER; and BLOOD-TESTIS BARRIER. Small lipid-soluble molecules such as carbon dioxide and oxygen move freely by diffusion. Water and water-soluble molecules cannot pass through the endothelial walls and are dependent on microscopic pores. These pores show narrow areas (TIGHT JUNCTIONS) which may limit large molecule movement. |
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Protein Transport - The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport. |
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Respiratory Transport - The processes of diffusion across the BLOOD-AIR BARRIER, and the chemical reactions coupled with diffusion that effect the rate of PULMONARY GAS EXCHANGE, generally at the alveolar level. |
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RNA Transport - The process of moving specific RNA molecules from one cellular compartment or region to another by various sorting and transport mechanisms. |
Biological Transport Definitions and Terms
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