Cell nucleus: control of cell functions
What is (definition)
The nucleus is responsible for controlling all cellular functions. Most cells in our body have a single nucleus. However, there are cells that have none (mature red blood cells) and others that have several, such as skeletal muscle cells.
Key Features of the Cell Core
Since not all cells have a defined nucleus, biology has divided them into two groups: eukaryotes (cells with a defined nucleus) and prokaryotes (cells without a defined nucleus).
Within these two groups, it is important to know that even prokaryotic cells have DNA. In this case, instead of concentrating in the nucleus, as with eukaryotic cells, DNA is usually found in the nucleoid.
The nucleoid is not a true nucleus, as it is not separated from the rest of the cell by its own membrane. This consists of a single large DNA molecule with associated proteins.
In the case of eukaryotic cells, the nucleus is separated by the nuclear envelope, which, besides having the function of separating the nucleus from the cytoplasm, communicates with the cytoplasm through the nuclear pores. These pores are responsible for controlling the exchange of substances between the nucleus and the cytoplasm.
Within the nucleus are bodies in spherical shapes called nucleoli, protein compounds, DNA and RNA, and nuclear genes, also known as the genetic code. These genes are responsible not only for hereditary characteristics, but also for controlling most of the activities performed by cells.
In general we can say that the nucleus has two basic functions: regulate the chemical reactions that occur inside the cell and store its genetic information.