Kapszidok

Kapszidok are protein shells that enclose the genetic material of viruses. They are made up of repeating protein subunits called capsomeres. The arrangement of these capsomeres determines the overall shape of the capsid, which can be icosahedral, helical, or complex.

Icosahedral capsids are the most common and have a spherical shape formed by 20 triangular faces. Helical capsids are rod-shaped, with capsomeres arranged in a spiral. Complex capsids have a combination of shapes and are found in viruses with more intricate structures.

The capsid plays a crucial role in protecting the viral genome from damage and in facilitating the virus's entry into host cells. It can also be involved in the virus's ability to recognize and bind to specific host cell receptors. The proteins that make up the capsid are encoded by the viral genome. After the virus infects a cell, these viral genes are transcribed and translated, producing the capsomere proteins. These proteins then self-assemble to form the new capsid around the replicated viral genetic material. The capsid is a fundamental component of viral structure and is essential for the viral life cycle.