Nucleus: Chemical constituents
Chemical constituents of Nucleus Nucleus is called apparatus of heredity. It is the largest extractoplasmic component of cell which contains all the genetic information to control morphology, function and heredity. It is called control room / director/heart of cell. A nucleus in metabolic phase (nondividing phase) I phase is called interphase nucleus. It is not an organelle of cell but component of protoplasm or called extractoplasmic organelle . Nucleus has DNA 9-12 % , RNA 5 % , Lipids 3 % and Ca , Mg , Mn , Na , P , Fe and K , 80 % proteins (65 % acidic non-histone which have height mol. wt., rich in tyrosine and tryptophan, forms enzymes, and helps in transciption of dNA to form RNA ; 15 % proteins are basic like, histone proteins of low mol. wt ., rich in lysine and arginine), DNA : histone ratio is roughly 1 : 1 . Histones neutralize acidity of nucleic acid and prevent transcription of dNA . Histones are structural proteins and suppress genes . Non- histones are functional ...
