Chromatin: the collective structure of all proteinsplugin-autotooltip__default plugin-autotooltip_bigProtein: a molecule that is formed by the translation of messenger RNAs (mRNAs). Functions that proteins provide are what usually give organisms their phenotypes. and DNAplugin-autotooltip__default plugin-autotooltip_bigDNA: deoxyribonucleic acid. The genetic material for nearly all life on Earth. in the nucleusplugin-autotooltip__default plugin-autotooltip_bigNucleus: in eukaryotes, the membrane-bound organelle in cells that contains the chromosomes. of a eukaryoticplugin-autotooltip__default plugin-autotooltip_bigeukaryote: organism whose cells have membrane bound organelles, including the nucleus. cell. Nucleosomesplugin-autotooltip__default plugin-autotooltip_bigNucleosome: In eukaryotes, approximately 146 bp of chromosomal DNA wraps around a histone octamer to form a nucleosome. The nucleosome is the basic unit of chromatin. are stacked in different configurations to form chromatin structures of different density. Chromatin structure is regulated by a variety of chromatin modifying enzymesplugin-autotooltip__default plugin-autotooltip_bigEnzyme: a macromolecule, usually a protein (but sometimes an RNA), that functions as a catalyst of some kind of biochemical reaction..