Nuclear envelope
From WikiLectures
The nuclear envelope separates the contents of the nucleus (ie, karyoplasm, chromatin fibrils, nucleolus) from the cytoplasm.
Structure[edit | edit source]
- Inner membrane - towards the inside contains a reticular network of protein molecules of 3 types (condensed parts of chromatin fibrils adhere to them, this enables the spatial separation of individual chromosomes in the preparation for their replication.
- Outer Membrane - transitions smoothly into the endoplasmic reticulum, ribosomes are often visible on it.
- Between them is the perinuclear space' (connected to the reticular cistern system).
Nuclear pore[edit | edit source]
- Octagonal openings, connecting the outer and inner membrane;
- 80 nm in diameter;
- the nucleus of a mammalian cell has 3000-4000;
- lined with a complex of 24 protein molecules with a closing granule;
- transports small protein molecules + large particles from the nucleus (ribosomal subunits, processed molecules mRNA);
- transport in the nuclear pores is massive, therefore regulation is necessary, but it has not yet been fully elucidated.
Links[edit | edit source]
Related Articles[edit | edit source]
References[edit | edit source]
- ŠTARK, Otakar – KAPRAS, Ján. Lékařská biologie a genetika 1. 1987. edition. Státní pedagogické nakladatelství, 1987. vol. 1.
