Cellnukleol
I de flesta typer av eukaryota cellkärnor utgör nukleolen en membranlös, avgränsad del, inom vilken några arter av rRNA (ribosomal RNA) syntetiseras och sätts samman till ribonukleoproteinenheter av r ibosomer. I nukleolen transkriberas rRNA från en nukleolär styrenhet, dvs en grupp (NOR - nucleolar organizer region) parvis upprepade kromosomgener som kodar för rRNA och som transkriberas av RNA-pol ymeras I.
The cell nucleolus is a suborganelle within the nucleus of eukaryotic cells, where ribosomal RNA (rRNA) genes are transcribed and processed into ribosomal subunits. It is a site of intense metabolic activity and is often observed as a dense, spherical structure in the nucleus during interphase. The cell nucleolus plays a crucial role in protein synthesis by providing the necessary machinery for the production of ribosomes, which are essential for translation of messenger RNA (mRNA) into proteins.
The nucleolus is a small, dense structure found within the cell nucleus of eukaryotic cells. It plays a central role in the production and assembly of ribosomal subunits, which are necessary for protein synthesis. The nucleolus is not surrounded by a membrane and is composed of three main regions: the fibrillar center, the dense fibrillar component, and the granular component. These regions are involved in various stages of ribosome biogenesis, including transcription of ribosomal RNA (rRNA) genes, processing and modification of rRNA, and assembly of ribosomal subunits. The nucleolus can change in size and number depending on the cell's needs, such as during periods of increased protein synthesis or stress.