the process by which cilia (see cilium) move a thin film of *mucus from the upper and lower respiratory tracts towards the digestive tract. Particles of dust and microorganisms are trapped on the mucus and thereby removed from the respiratory tract.
(in biochemistry) an energy-dependent process in which certain substances (including ions, some drugs, and amino acids) are able to cross cell membranes against a concentration gradient. The process is inhibited by substances that interfere with cellular metabolism (e.g. high doses of digitalis).... active transport
a series of enzymes and proteins in living cells through which electrons are transferred, via a series of oxidation-reduction reactions. This ultimately leads to the conversion of chemical energy into a readily usable and storable form. The most important electron transport chain is the respiratory chain, present in mitochondria and functioning in cellular respiration.... electron transport chain
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