Controlling insulin production with a smartwatch

Many modern fitness trackers and smartwatches feature integrated LEDs. The green light emitted, whether continuous or pulsed, penetrates the skin and can be used to measure the wearer's heart rate during physical activity ...

Resetting the biological clock by flipping a switch

The biological clock is present in almost all cells of an organism. As more and more evidence emerges that clocks in certain organs could be out of sync, there is a need to investigate and reset these clocks locally. Scientists ...

Protein can release trapped histones in the cell

In the cell nucleus, histones play a crucial role packaging DNA into chromatin. Histones are however very sticky to both DNA and RNA, so to ensure they are transported to the cell nucleus after synthesis and bind to the right ...

Researchers probe cell nucleus response with needle-tip technique

Kaitlin McCreery is the coauthor of a new paper published in Small that deals with diagnosing diseases such as osteoarthritis in soft tissue. McCreery is currently a Ph.D. student in the Neu Lab where she studies the biophysical ...

Researchers report new technique to image the cell nucleus

Nestled deep in the nucleus of each of your cells is what seems like a magic trick: Six feet of DNA is packaged into a tiny space 50 times smaller than the width of a human hair. Like a long, thin string of genetic spaghetti, ...

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Cell nucleus

In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, or kernel), also sometimes referred to as the "control center", is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression--the nucleus is therefore the control center of the cell.

The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and separates its contents from the cellular cytoplasm, and the nuclear lamina, a meshwork within the nucleus that adds mechanical support, much like the cytoskeleton supports the cell as a whole. Because the nuclear membrane is impermeable to most molecules, nuclear pores are required to allow movement of molecules across the envelope. These pores cross both of the membranes, providing a channel that allows free movement of small molecules and ions. The movement of larger molecules such as proteins is carefully controlled, and requires active transport regulated by carrier proteins. Nuclear transport is crucial to cell function, as movement through the pores is required for both gene expression and chromosomal maintenance.

Although the interior of the nucleus does not contain any membrane-bound subcompartments, its contents are not uniform, and a number of subnuclear bodies exist, made up of unique proteins, RNA molecules, and particular parts of the chromosomes. The best known of these is the nucleolus, which is mainly involved in the assembly of ribosomes. After being produced in the nucleolus, ribosomes are exported to the cytoplasm where they translate mRNA.

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