* More than 40 proteins and glycoproteins involved in the complement system are synthesized by the liver, macrophages, epithelial cells, they are present in the blood in plasmatic form, membrane, some have an enzymatic activity, regulator or membrane receptorThese are elements of the humoral innate immune response, they fight infections, purify immune complexes and apoptotic bodies. <span>There are indeed three ways to activate the complement:</span> Classical pathway: Activated by Immunoglobulins in immune complexes, aggregated Immunoglobulins, DNA, CRP, apoptotic bodies .......it involves nine fractions, starting with C1, then C4, C2, C3, to form a classical C5 convertase, then, activation of C5, C6, C7, C8, C9.
Alternative pathway: activated by polysaccharides (bacterial endotoxin), vascular wall poor in sialic acid, aggregated IgE ...C3b like is the first component in the alternate channel cascade, it will create an amplification loop, and form an alternative C5 convertase.
Lecithin pathway: Activated by mannose, fucose (carbohydrate of microorganisms)The first component is the complex MBL / MASP1 / MASP2: "mannose-binding protein": works according to the same principle as the complex C1 of the classical way (MASP2 cleaves the C4 and the rest of the cascade is equivalent to that of the classical way).
the three ways have the same outcome: A C5 convertase (formed by one of the pathways) cleaves C5 into C5a and C5b: C5b is deposited far from other fractions on the antigenic surface. The fixation of C5b in the cell is followed by that of C6, C7, C8, and C9 (9 molecules of C9): formation of the membrane attack complex (MAC) ==> Death of the cell by osmotic shock
Multicellular organism is the example of complexity of the natural world.
Explanation:
Multicellular organism such as human which is made of billions of cell. Each cell perform a specific function. The function of one organ is different from the other organ. For example, brain of human is made of millions of neurons which takes instructions from brain to the organs and bring messages from organs to the nervous system in the form of electrical impulses. In short every system in our body is full of complexity.
Hemoglobin has tetrahedral structure containing four heme groups that surround a globin group.
Heme is ringlike organic compound also known as a porphyrin to which an iron atom is attached. There are four iron atoms that bind four oxygen atoms and transport them to tissues.
The structure of the cell is very much linked with the functions of the cell.The cardiac muscle is made of myocardium which serves the body by providing the blood, nutrients and oxygen.The cardiac muscles appears stripped when seen under microscope.
The skin consists of the tissues and cells which are close enough to create a boundary which does not allows the entry of materials and pathogens inside the body.
Hence, the function and the morphology of the cells are somewhere related to each other.
