NUCLEOPLASM OR KARYOPLASM OR KARYOLYMPH OR NUCLEAR SAP
Nucleoplasm and cytoplasm name proposed by E. Strassburger. Chemical composition of nucleoplasm given by Kossel. Compositions of nucleoplasm is similar to cytoplasm but it contains high concentration of nucleotides in form of triphosphates. Nucleoplasm have enzymes for glycolysis. Thus nucleus obtains its own energy by glycolytic pathway.
Inside nucleoplasm, there is a net work of fine threads. These threads called chromatin fibers. Chormatin name proposed by Flemming. Chromatin threads composed of DNA, RNA, histone protein & nonhistone protein. Chromatic threads contain genetic information Alkaline stain (Acetocarmine, Haematoxylene, Feulgen) are used to stain chromatin. In stained preparation under light compound microscope chromatin net work appears differentiated in two parts :-
1. Euchromatin - Lightly stained thin and diffused part of chromatin. This part have less histone and more acidic proteins. Euchromatin is more active part of Chromatin and its DNA undergoes rapid transcription. During nuclear division euchromatin replicates in S-phase of cell cycle. It is affected by pH, temperature, poisons etc. It takes part in crossing over. It is formed by loose spiralisation of nucleosome strands.
2. Hetrochromatin - Darkly stained thick and condensed part of chromatin. This part have more histone and less acidic proteins Heterochromatin is genetically a less active part of chromatin. Heterochromatin forms stop points in transcription.