Q:

What is the function of a nucleolus?

A:

Quick Answer

The function of the nucleolus is to transcribe DNA into ribosomal RNA and assemble rRNA into ribosomal subunits. The creation of rRNA is important because rRNA makes up ribosomes which are responsible for protein synthesis in the cell.

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What is the function of a nucleolus?
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In order for transcription to occur, a protein called RNA polymerase binds to DNA at its promoter region. Transcription factors and proteins pull apart DNA's double helix so that polymerase can then transcribe one strand of the DNA to create single-stranded RNA. Transcription ends when polymerase reaches a terminator sequence on the DNA.

When DNA is transcribed into rRNA in the nucleolus, three or four (depending on the organism) distinct rRNAs are produced. These rRNAs are combined with proteins in order to assemble a large ribosomal subunit and a small ribosomal subunit. The subunits are then exported from the nucleolus and nucleus to the endoplasmic reticulum and the cell's cytosol in order to carry out the process of translation, or protein synthesis.

Nucleoli are made of proteins, DNA and RNA and are contained within the cell's nucleus. They don't have membranes, so they can disassemble when the cell divides during mitosis. While humans only have one nucleolus per cell, other organisms exist that can have cells containing multiple nucleoli.

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Related Questions

  • Q:

    What is a dense area in a cell that contains nucleic acids?

    A:

    The dense area within a cell that contains nucleic acids is known as the nucleolus. The nucleolus is responsible for assembling ribosomes, which are essential to protein production and organization in a cell.

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  • Q:

    What is inside the nucleus?

    A:

    The cell nucleus of a eukaryote contains a nucleolus, chromatin, ribosomes, nucleoplasm and pores. However, the nuclear envelope surrounds the nucleus and consists of an inner and outer membrane with pores. These pores are present to regulate the flow of materials like messenger RNA and protein moving through the membrane.

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  • Q:

    What happens in the nucleolus?

    A:

    The nucleolus is chiefly responsible for creating ribosomes, which in turn function as factories for protein synthesis. The nucleolus contains three main organizing regions where transcription and processing of rRNA occurs. It also purportedly aids in other processes, like the packaging of signal recognition particles and the alteration of transfer RNA. The nucleolus is located in the nucleus, and thus only exists in eukaryotic cells.

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  • Q:

    What is a good analogy for the functioning of the nucleolus?

    A:

    The best analogy for the nucleolus in eukaryotic cells is a factory that makes tools that are used to build other resources. The primary function of the nucleolus is to combine and construct ribosomes. The primary function of ribosomes is to build proteins necessary for the cell.

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