cellekjerne

Cellekjerne is the Norwegian word for cell nucleus. The cell nucleus is a membrane-bound organelle that contains the genetic material of eukaryotic cells. It is typically the most prominent organelle within a cell, playing a central role in cell division, growth, and heredity.

The nucleus is enclosed by a double membrane called the nuclear envelope, which separates its contents from the cytoplasm. This envelope is perforated by nuclear pores that regulate the passage of molecules into and out of the nucleus. Inside the nucleus, the genetic material is organized into chromosomes, which are composed of DNA tightly wound around proteins called histones. During cell division, these chromosomes condense and become visible under a microscope.

The nucleus also contains a specialized structure called the nucleolus. The nucleolus is primarily responsible for ribosome synthesis, a crucial process for protein production in the cell. The fluid-filled space within the nuclear envelope is known as the nucleoplasm, which contains various proteins and molecules necessary for nuclear function, including enzymes involved in DNA replication and transcription.

The presence of a well-defined nucleus is a hallmark of eukaryotic cells, distinguishing them from prokaryotic cells which lack such an organelle. The nucleus's function is vital for the proper functioning and survival of eukaryotic organisms.