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A graph showing the ef-fect of different wavelengths of radiation,usually light,on a given process. It is oftensimilar to the absorption spectrum of the sub-stance that absorbs the radiation and cantherefore be helpful in identifying that sub-stance. For ...[继续阅读]
Symbol: Ea The mini-mum energy a particle,molecule,etc.,must acquire before it can react; i.e. theenergy required to initiate a reaction regard-less of whether the reaction is exothermic orendothermic. Activation energy is often rep-resented as an energy ...[继续阅读]
The region of an enzymemolecule that combines with and acts on thesubstrate. It consists of amino acids arrangedin a configuration specific to a particular sub-strate or type of substrate. Binding of an in-hibiting compound elsewhere on the enzymemolecule...[继续阅读]
The transport of moleculesor ions across a cell membrane against a concen-tration gradient,with the expenditure of energy:it is probably an attribute of all cells. Anythingthat interferes with the provision of energy willinterfere with active transport. T...[继续阅读]
A protein complex found inmuscle,formed between molecules of actinand myosin present in adjacent thick and thinmuscle filaments. These actomyosin com-plexes are involved in the process of musclecontraction; their formation is important inthe concerted mec...[继续阅读]
1 . The extent to which an or-ganism,or a physiological or structural char-acteristic of an organism,is suited to a par-ticular environment. Organisms that have be-come highly adapted to one environment arethen often not so adaptable as less specializedor...[继续阅读]
Anenzyme that is produced by a cell only in thepresence of its substrate. Compare constitu-tive enzyme.细胞只在其底物存在时才能产生的 一种酶。比较196页constitutive enzyme。...[继续阅读]
The gradual formationthrough evolution of a number of different va-rieties or species from a common ancestor,each adapted to a different ecological niche.A classic example of adaptive radiation is il-lustrated by Darwins finches. See alsoDarwins finches.从...[继续阅读]
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