NUCLEOLUS Dr Trayee Biswas NUCLEOLUS The nucleolus cellular

NUCLEOLUS Dr Trayee Biswas

NUCLEOLUS �The nucleolus cellular structure is a round body located inside nucleus of eukaryotic cell and takes up 25% of the nucleus. Instead of being surrounded by a membrane, the nucleolus sits in the middle of the nucleus.

NUCLEOLUS �The function of nucleolus is to copy and manufacturing ribosomal subunits from proteins and r. RNA (ribosomal RNA), ribosome assembly, and is where transcription of r. RNA takes place.

NUCLEOLUS � The nucleolus structure is made up of two key components: � A dense fibrillar component (DFC), � A fibrillar centers (FC). The fibrillar component can be divided into two compartments: a dense fibrillar component and a fibrillar center. The centers of the fibrillars contain big amounts of RNA polymerase I, which copies r. RNA. The structure gathers around clusters of r. RNA gene during late telophase, continues through interphase, and then breaks apart when the cells go into mitosis.

NUCLEOLUS � The nucleolus is like a factory that makes tools. The nucleolus produces ribosomes � The difference with the nucleolus and a factory is that a factory is much larger that the nucleolus which is microbial, factories need artificial energy (electricity) to functions whereas the nucleolus doesn't because it produces its own, and a factory is operated by humans whereas the nucleolus is operated by the cell itself.

NUCLEOLUS � Nucleoli are formed around specific genetic loci called nucleolar organizing regions (NORs), NOR is composed of tandem repeats of r. RNA genes. The human genome contains more than 200 clustered copies of the r. RNA genes on five different chromosomes (13, 14, 15, 21, 22).

NUCLEOLUS �The nucleolus function is to copy and manufacturing ribosomal subunits from proteins and r. RNA (ribosomal RNA), ribosome assembly, and is where transcription of r. RNA takes place.

NUCLEOLUS � Without the nucleolus, there would be no ribosomes, thus no proteins being made. It's affect also can be applied to all the organelles since a majority of them are made of proteins. � The cell would not be able to exist without the nucleolus because all of its processes within different organelles would be affected.

Ribosome Biogenesis

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