A graph showing theeffect of different wavelengths of radiation,usually light,on a given process. It is oftensimilar to the ABSORPTION SPECTRUM of the substance that absorbs the radiation andcan therefore be helpful in identifying thatsubstance. For examp...[继续阅读]

    A three-dimensional re-gion (domain) of an ACTIVATOR-a type oftranscription factor that can activate genetranscription when the transcription factor isbound to the DNA molecule via another do-main (the DNA-binding domain). Activatorscan have more than one...[继续阅读]

    The amount of energyrequired for a reaction to proceed.It is de-termined by the free energy of any intermedi-ates formed in the reaction ,which tends tobe greater than that of either reactants orproducts. Enzymes accelerate the rate of re-actions by reduc...[继续阅读]

    A type of TRANSCRIPTIONFACTOR that activates transcription of agene or genes. Activators are proteins thatbind to DNA via specific molecular regionscalled DNA-binding domains,and interactwith other transcription factors by means ofone or more ACTIVATION D...[继续阅读]

    The region of an enzyme moleculethat combines with and acts on the substrate.Itconsists of amino acids arranged in a configura-tion specific to a particular substrate or type ofsubstrate. An active site performs two func-tions: it binds the substrate,and ...[继续阅读]

    The transport of moleculesor ions across a cell membrane against a con-centration gradient or electrochemical gradientthrough the expenditure of energy. Anythingthat interferes with the provision of energywill interfere with active transport. Themechanism...[继续阅读]

    A protein complex found inMUSCLE,formed between molecules of actinand myosin present in adjacent thin and thickmuscle filaments. Actomyosin complexes areinvolved in muscle contraction,particularlyin the mechanism that pulls the thin filamentspast the thic...[继续阅读]

    See glyceride参阅glyceride。...[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.2. (accommodation) The decrease with timeof the frequency of response of sensory recep-tors subjected to a constant...[继续阅读]

    1. A protein componentof CLATHRIN-COATED PITS and vesicles.The latter arise from invaginations of mem-branes,and function in transporting materialsaround the cell. As a pit forms in a mem-brane,the adapter proteins bind to mem-brane proteins and form asse...[继续阅读]