Chapter -3 Flashcards
(17 cards)
Nucleus
Contains cell enzymes and proteins
main site for DNA replication and RNA synthesis and processing
Proteins needed for nuclear activity are imported from cytoplasm
Components of nucleus
Nuclear envelop
Nucleolus
Chromatin
Mesh work of proteins in the inner nuclear membrane that stabilizes nuclear envelope
Nuclear lamina
Chromatids
After DNA replication but before cell division each chromosomes consist of 2 identical chromatin units called chromatids
Held by cohesin proteins
Basic proteins in DNA
Histones
8 histone proteins
H2A , H2B ,H3, H4 (✖️2)
Histones is wrapped ,
150 bp of DNA
Structural unit of DNA + Histones =>
Nucleosome
Amino acids in positively charged histones ?(Histones are LARGe )
Lysine and ARGinine
___________have their own DNA, which is
circular and does not utilize histones
Mitochondria
HeteroChromatin
Highly Condensed
Appears darker
Electron dense material in EM
Basophilic in LM
Sterically inaccessible
Transcriptionally inactive
Euchromatin
Expressed
Less condensed
Appears light on EM
Transcriptionally active
Stericaly accessible
Genomic material present in heterochromatin
Constitutive
Facultative
Names of genomic materials in heterochromatin ?
Constitutive HC
Facultative HC
New method of chromosomal staining and molecular techniques are continuously being developed and used for cytogenetic diagnosis
FISH - fluorescence in-situ hybridisation
The newly organized small and large ribosomal subunits are then exported back to the cytoplasm through those same nucleolus
✔️
✖️
✖️
Ans) nuclear pores
The ___________ is a generally spherical, highly basophilic sub- domain of nuclei in cells actively engaged in protein synthesis
Nucleolus
