Kevin
December 12, 2021
Common Questions
Do you know what the complement is? This article will provide you with all of the information you need on complements, including its definition, usage, example sentences, and more!
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According to NCBI, the complement system is a major mechanism by which pathogen recognition is converted into an effective host defense against initial infection. It augments the opsonization of bacteria by antibodies and allows antibodies to kill some bacteria, this complementing the antibacterial activity of antibody. This creates antigens for an immune response. They promote inflammation attracting macrophages and neutrophils, and attack the pathogen’s cell membrane.
Complement is a system of plasma proteins that interacts with pathogens, thus marking them for destruction by phagocytes. This classical pathway is initiated by the binding of C1 q to the pathogen surface. The MB-lectin pathway is initiated by binding of the serum protein to mannose-containing carbohydrates in bacteria or viruses. Many complement proteins are proteases are activated by proteolytic cleavage. Many different things can be bound, including C1q, C3a, C9, C1r, C1s, C4, C2, C5A, C7, C6, C8, C4A, C3 convertase, C3B, C3BBB, C4B, C5 convertase, CD46, C1-complex, C2A, C2BDAF, IGM, CR2, CR1, CR3, C5AR, AP, SLE, B cells, T-cell, CH50, C1-Inh, and more. Some are stabilized by properdin. C1r is a serine protease. There are diseases associated with complement deficiencies. There are many factors including factor B, factor H, and factor D that bind and release the proteins.
Overall, complement is a system of plasma proteins. There are three different pathways of complement activation. First there is the classical pathway, which is triggered directly by a pathogen or triggered indirectly by antibody binding to the pathogen surface. The other two pathways are the MB-lectin pathway and the alternative pathway, which also provides an amplification loop.
A sequence of cleavage reactions occur in which the larger cleavage product is able to bind covalently to the pathogen’s surface which then contributes to the activation of the next component. The binding of C3b molecules to the pathogen is the main event in complement activation, because then complement components, inactive fragments, are recognized by complement receptors on phagocytic cells, which then engulf pathogens. The fragments recruit phagocytes to infection and activate them by binding to specific receptors. Then, they promote the uptake and destruction of pathogens by phagocytes and a fragment triggers the assembly of a membrane-attack complex, which can result in the cell lysis of certain pathogens. This activity of complement components is regulated by regulatory proteins that prevent tissue damage as a result of binding of activated complement components to host cells or activation of complement components in plasma.
According to Your Dictionary, a complement in grammar is a word, clause, or phrase that’s needed to describe the subject or object of a sentence. These often follow linking verbs, which show connection rather than action. These can be a noun, an adjective, a single word, or a group of words that act like a noun or adjective, with subject complements further broken down into predicate nominatives and predicate adjectives.
See below for examples of complements from Your Dictionary and Thought Co:
Many different languages also contain words that mean complement. You may notice that some of these translations of complement look and sound similar to one another. These are called cognates, which are words and phrases in different languages that likely have the same root or language of origin, causing them to sound the same. The below list of translations of complement is provided by Word Sense.
Overall, a complement is a term in grammar and in science. In grammar, a complement in grammar is a word, clause, or phrase that’s needed to describe the subject or object of a sentence. In science, the complement system is a major mechanism by which pathogen recognition is converted into an effective host defense against initial infection.
