The transport of mole-cules or ions across a cell membrane against aconcentration gradient,with the expenditureof energy: it is probably an attribute of allcells. Anything that interferes with theprovision of energy will interfere with ac-tive transport. ...[繼續(xù)閱讀]

    A protein complex found inmuscle,formed between molecules of AC-TIN and MYOSIN present in adjacentthick and thin muscle filaments. These ac-tomyosin complexes are involved in theprocess of muscle contraction; their forma-tion is important in the concerted...[繼續(xù)閱讀]

    A chemical reaction in which anacyl group is introduced into a compound.將?；鶎?dǎo)入某化合物的一種化學(xué)反應(yīng)。...[繼續(xù)閱讀]

    An organic group with thegeneral formula R - CO -。The acetylgroup,CH3 -CO-is a simple example.有機基團,其通式為R-CO-。如乙?；鵆H3-CO—。為一簡單的?；?..[繼續(xù)閱讀]

    Anenzyme that is produced by a cell only inthe presence of its substrate. Compare con-stitutive enzyme.只有當(dāng)酶底物存在的情況下細胞才能產(chǎn)生的一種酶。比較constitutive enzyme。...[繼續(xù)閱讀]

    A reaction in which ad-ditional atoms or groups of atoms are in-troduced into an unsaturated compound. Asimple example is the addition of bromineacross the double bond in ethene:H2C:CH2+Br2 →BrH2CCH2BrAddition reactions can be induced ei-ther by electroph...[繼續(xù)閱讀]

    A compound formed by direct ad-dition of two chemical species,especiallyone produced by forming a coordinate bondbetween a donor and an acceptor.通過兩類化學(xué)試劑的直接加成得到的化合物。特指電子供體和受體通過配位鍵形成的化合物。Adenine腺嘌呤...[繼續(xù)閱讀]

    A nitrogenous base found inDNA and RNA. It is also a constituent ofcertain coenzymes,e. g. NAD and FAD,and when combined with the sugar ribose itforms the nucleoside adenosine found inAMP,cAMP,ADP,and ATP. Adenine hasa purine ring structure. See also DNA....[繼續(xù)閱讀]

    A NU-CLEOSIDE formed from adenine linked toD-ribose with aβ-glycosidic bond. It iswidely found in all types of cell,either asthe free nucleoside or in combination in nu-cleic acids. Phosphate esters of adenosine,such as ATP,are important carriers of en-er...[繼續(xù)閱讀]

    See ADP參閱ADP。...[繼續(xù)閱讀]