See micro-scope .參閱micro-scope。...[繼續(xù)閱讀]

    American bio-chemist who discovered that proteins haveintrinsic signals that govern their transportand localization in the cell. He was awardedthe 1999 Nobel Prize for physiology or medicine.美國生物化學(xué)家,因發(fā)現(xiàn)蛋白質(zhì)的內(nèi)在信號控制它們的轉(zhuǎn)運和在細胞內(nèi)的定位被授予1...[繼續(xù)閱讀]

    Any method of datingthat uses the decay rates of naturally oc-curring radioactive isotopes to assess theage of a specimen. Organic matter less than7000 years old can be dated using radiocar-bon dating. This uses the fact that the iso-tope carbon-14 is fou...[繼續(xù)閱讀]

    A type of organic compound ofgeneral formula RCONH2 (primary),(RCO)2NH (secondary),and (RCO)3N(tertiary). Amides are white,crystallinesolids and are basic in nature,some beingsoluble in water.一種有機化合物,通式為RCONH2(一級,伯胺)、(RCO)2NH(二級,仲胺)和(RCO)3N(三級,叔胺)。酰胺...[繼續(xù)閱讀]

    The potential differencethat exists across the cell membrane of anonconducting neurone. It is produced andmaintained by the sodium pump,which ac-tively expels sodium ions from the cell andthereby builds up a positive charge on theoutside of the membrane. ...[繼續(xù)閱讀]

    A colorlessvolatile liquid alcohol,C2H5OH.Ethanol oc-curs in intoxicating drinks,in which it is pro-duced by fermentation of a sugar:C6H12O6→2C2H5OH+2CO2Yeast is used to cause the reaction. At about15% alcohol concentration (by volume) the re-action stops...[繼續(xù)閱讀]

    Genes that are essentialfor cell activity and are expressed in almostall cells. Expression does not require anyspecific activation factors.細胞活動的必需基因,并且表達于所有細胞。其表達不需任何特殊的活化因子。...[繼續(xù)閱讀]

    The study of the form of or-ganisms. The term may be used synony-mously with ‘a(chǎn)natomy’ although generallythe study of external form is termed‘morphology’ while the study of internalstructures is termed ‘a(chǎn)natomy’.研究生物體形態(tài)的學(xué)科。該術(shù)語可用作解剖學(xué)同義詞,雖然通...[繼續(xù)閱讀]

    The phenomenon in which theaffinity of the respiratory pigment of theblood (hemoglobin in vertebrates) for oxy-gen is reduced as the level of carbon dioxideis increased. This facilitates gaseous ex-change,because more oxygen is released inthe tissues wher...[繼續(xù)閱讀]

    One of a group of acidic substancesoccurring in many trees and shrubs (e. g.conifers and some poplars) either as stickyglassy solids or in solution in essential oils,i. e. as balsams,such as turpentine. Resinsmay be phenolic derivatives or oxidationproduc...[繼續(xù)閱讀]