Kaitsevalkude

Kaitsevalkude, also known as defense proteins or resistance proteins, are molecules that play a crucial role in protecting organisms from various threats. In plants, these proteins are part of a complex immune system that helps them defend against pathogens like bacteria, fungi, and viruses. When a plant detects a pathogen, it can trigger the production of specific defense proteins that either directly inhibit the pathogen's growth or activate other defense mechanisms. Examples include pathogenesis-related (PR) proteins, which have diverse functions such as enzyme inhibition or the breakdown of pathogen cell walls.

In animals, the concept of defense proteins is broad and encompasses a wide range of molecules involved in immunity. Antibodies, for instance, are a critical type of defense protein produced by B cells that specifically bind to foreign substances (antigens) like viruses and bacteria, marking them for destruction. Other defense proteins include antimicrobial peptides, which can directly kill bacteria and fungi, and complement proteins, a group of blood proteins that work together to eliminate pathogens and inflamed tissue. These proteins are essential for maintaining the health and survival of multicellular organisms by constantly monitoring and responding to internal and external challenges.