What do you need the nuclear pores for?
The pores in the membrane are complex channels with a diameter of 60 to 100 nm, which form a physiological barrier between the nucleus and the cytoplasm. They are required for the transport of certain molecules to or from the cell nucleus. These molecules include, for example, mRNA, which plays a major role in replication and subsequent translation. The DNA is first written off in the cell nucleus, resulting in mRNA. This copy of the genetic material leaves the cell nucleus via a nuclear pore and reaches the ribosomes, where translation takes place.
Tasks of the cell nucleus
Two elementary biological processes take place in the cell nucleus: on the one hand the replication of DNA and on the other hand the transcription, i.e. the transcription of DNA into RNA. During cell division (mitosis), DNA doubles (replication). Only after the entire genetic information has been doubled can the cell divide and thus form the basis for growth and cell renewal.
During transcription, one of the two strands of DNA is used as a template and converted into a complementary RNA sequence. A variety of transcription factors determine which genes are transcribed. The resulting RNA is modified in many further steps. The stable end product, which can be exported into the cytoplasm and ultimately translated into protein building blocks, is called messenger RNA (mRNA).
What happens during cell division?
A cell nucleus division is the division of a cell nucleus, which can take place in two different ways. The two types, mitosis and meiosis, differ in their sequence of events and also in their function. Depending on the type of nuclear division, different daughter cells are obtained.
After the end of mitosis, two daughter cells identical to the mother cell are obtained, which also have a diploid chromosome set. This type of cell nuclear division predominates in the human organism. Its function is the renewal of all cells, such as skin cells or mucous membrane cells.
Mitosis occurs in several phases, but there is only one real chromosome division. In contrast, meiosis consists of two nuclear divisions. The result of a completed meiosis are four cells containing a haploid set of chromosomes. These germ cells are necessary for sexual reproduction and are therefore only found in sexual organs. When egg and sperm fuse during fertilization, two haploid sets of chromosomes result in a cell with a diploid set of chromosomes.
All articles in this series:
