Euchromatin(redirected from euchromatic)
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(also active chromatin), the portion of the chromatin that retains the uncoiled form of elementary deoxyribonucleoprotein (DNP) threads in the interval between cell divisions (that is, in the interphase), as opposed to the portion of the chromatin known as heterochromatin, which retains the coiled form. Euchromatin also differs from heterochromatin in that it participates in the intensive synthesis of ribonucleic acid (RNA) and contains a larger quantity of nonhistone proteins. Euchromatin contains not only DNP but also ribonucleoprotein granules, which have a diameter of 200–500 angstroms and serve to complete the maturation of the RNA and its transfer into the cytoplasm. Euchromatin contains most of the structural genes of an organism (seeCHROMOSOME).