Encyclopedia of Chemistry

Dam, Henrik (1895–1976) DanishBiochemist Carl Peter Henrik Dam was born in Copenhagen on Febru- ary 21, 1895, to druggist Emil D ...

fied as a university lecturer in 1910 after having obtained a Ph.D. in physics in 1908 there. In 1911 he went on to become profe ...

degenerate chemical reaction SeeIDENTITY REAC- TION. degenerate rearrangement A MOLECULAR REAR- RANGEMENTin which the principal ...

De-nol Trade name for the potassium salt or mixed ammonium potassium salt of a bismuth citrate com- plex, used in the treatment ...

increase in potential becoming more negatively and less positively charged. Repolarization is when the state returns to its rest ...

dextrorotatory Refers to an optically active sub- stance or compound that rotates plane-polarized light clockwise (to the right) ...

differential thermometer A thermometer used for accurate measurement of very small changes in temper- ature; usually consists of ...

dimerization The TRANSFORMATIONof a MOLECULAR ENTITYA to give a molecular entity A 2. For example: CH 3 .+ H 3 C.→CH 3 CH 3 2 CH ...

diradical SeeBIRADICAL. direct effect SeeFIELD EFFECT. disaccharide A class of sugar, a carbohydrate, cre- ated by linking a pai ...

RC.HCH 3 + R′C.HCH 3 →RCHCH 2 + R′CH 2 CH 3 are also loosely described as radical disproportionations. disrotatory SeeELECTROCY ...

distillation The creation of a purified liquid by con- densing from a vapor produced during distilling (boiling). distomer The E ...

DNA probe 81 What a Crime Lab Does, It Does with Chemistry by Harry K. Garber Much as a car runs on gasoline, a crime lab runs o ...

82 DNA probe A primary function of the firearms section is to deter- mine whether a questioned bullet (for example, removed from ...

and binds specifically to a complementary DNA sequence. The probe is used to detect its incorporation through hybridization with ...

was awarded the 1939 Nobel Prize in physiology or medicine for his discovery. He died on April 24, 1964. domain An independently ...

phosphate solvent. The strands are antiparallel, thus the phosphodiester bonds run in opposite directions. As a result, the stru ...

d-transition elements (metals) Transition elements are elements that can form bonds with the electrons from the outer two shells ...

EC nomenclature for enzymes A classification of ENZYMEs according to the Enzyme Commission of the International Union of Biochem ...

of an analogous INTERMOLECULARelementary reaction. This ratio has the dimension of concentration. The term can also apply to an ...

At the death of his father, the family moved to Hol- land and settled in Utrecht, where he attended school. In 1878 he entered t ...