A compound or unit produced by the combination of two like molecules; in the strictest sense, without loss of atoms (thus nitrogen tetroxide, N2O4, is the d. of nitrogen dioxide, NO2), but usually by elimination of H2O or a similar small molecule between the two ( e.g., a disaccharide), or by simple noncovalent association (as of two identical protein molecules); higher orders of complexity are called trimers, tetramers, oligomers, and polymers. [G. di-, two, + -mer]
- pyrimidine d. a product of ultraviolet radiation of pyrimidines in nucleic acid s; most frequently thymidine dimers.
- thymine d. a product of ultraviolet irradiation of thymine (free in ice or bound in nucleic acid s) in which two thymine residues become linked by formation of a cyclobutane ring involving both C-5's and both C-6's at the expense of the two double bonds; several stereoisomeric forms are possible.
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di·mer 'dī-mər n a compound formed by the union of two radicals or two molecules of a simpler compound specif a polymer formed from two molecules of a monomer
di·mer·ic (')dī-'mer-ik adj
di·mer·iza·tion or Brit di·mer·isa·tion .dī-mə-rə-'zā-shən n
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di·mer (diґmər) 1. a compound formed by combination of two identical simpler molecules. 2. a capsomer having two structural subunits.Medical dictionary. 2011.