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Agglutinogen
Agglutinogen is an antigen that causes the formation of agglutinins in the body and leads to agglutination, such as hemagglutination, which involves red blood cells (RBCs). The kind of agglutinogens present on the red blood cells helps determine the blood type of a person. For example, in the ABO blood type classification system, if a person has blood type A, then the red blood cells exhibit agglutinogens A or antigens A. If the blood is of type B, the agglutinogens present are of type B. If the blood is of type AB, then both agglutinogens A and B are present. In blood type O, there are no agglutinogens on the surface of the red blood cells. The agglutinogens are made by specific enzymes, which are encoded in genes. Different versions, or alleles give rise to different agglutinogens: the A allele codes for an enzyme that makes the agglutinogen A and similarly the B allele results in the agglutinogen B. A third version of this gene, the O allele, codes for a protein that is not fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of simple sugars), lipids, or nucleic acids. Antigens exist on normal cells, cancer cells, parasites, viruses, fungus, fungi, and bacteria. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, antibodies are ''antigen-specific'', meaning that an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agglutinin
An agglutinin is a substance in the blood that causes particles to coagulate and aggregate; that is, to change from fluid-like state to a thickened-mass (solid) state. Agglutinins can be antibodies that cause antigens to aggregate by binding to the antigen-binding sites of antibodies. Agglutinins can also be any substance other than antibodies, such as sugar-binding protein lectins. When an agglutinin is added to a uniform suspension of particles, such as bacteria or blood, in a test tube (in vitro), agglutinin binds to the agglutinin-specific structure on the particle causing the particles to aggregate and fall to the bottom, leaving a clear suspension. This phenomenon known as agglutination is of great importance in medicine, as it serves as a diagnostic tool. Medical relevance Reaction of particles with agglutinin is used to indicate present or past host contact with a pathogen. A host infected with a pathogen produces antibodies to neutralize the pathogen. As a result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agglutination
In linguistics, agglutination is a morphology (linguistics), morphological process in which words are formed by stringing together morphemes (word parts), each of which corresponds to a single Syntax, syntactic feature. Languages that use agglutination widely are called agglutinative languages. For example, in the agglutinative Turkish language, Turkish, the word ("from your houses") consists of the morphemes ''ev-ler-i-n-iz-den''. Agglutinative languages are often contrasted with isolating languages, in which words are monomorphemic, and fusional languages, in which words can be complex, but morphemes may correspond to multiple features. Examples of agglutinative languages Although agglutination is characteristic of certain language families, this does not mean that when several languages in a certain geographic area are all agglutinative they are necessarily related phylogenetically. In the past, this assumption led linguists to propose the so-called Ural–Altaic languages, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemagglutination
Hemagglutination, or haemagglutination, is a specific form of agglutination that involves red blood cells (RBCs). It has two common uses in the laboratory: blood typing and the quantification of virus dilutions in a haemagglutination assay. Blood typing Blood type can be determined by using antibodies that bind to the A or B blood group antigens in a sample of blood. For example, if antibodies that bind the A blood group are added and agglutination occurs, the blood is either type A or type AB. To determine between type A or type AB, antibodies that bind the B group are added and if agglutination does not occur, the blood is type A. If agglutination does not occur with either antibodies that bind to type A or type B antigens, then neither antigen is present on the blood cells, which means the blood is type O. In blood grouping, the patient's serum is tested against RBCs of known blood groups and also the patient's RBCs are tested against known serum types. In this way th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Blood Cell
Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen () to the body tissue (biology), tissues—via blood flow through the circulatory system. Erythrocytes take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillary, capillaries. The cytoplasm of a red blood cell is rich in hemoglobin (Hb), an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological Cell (biology), cell function such as erythrocyte deformabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Type
A blood type (also known as a blood group) is based on the presence and absence of antibody, antibodies and Heredity, inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. Some of these antigens are also present on the surface of other types of Cell (biology)#Eukaryotic cells, cells of various Tissue (biology), tissues. Several of these red blood cell surface antigens can stem from one allele (or an alternative version of a gene) and collectively form a blood group system. Blood types are inherited and represent contributions from both parents of an individual. As of October 2024, a total of 47 human blood group systems are recognized by the International Society of Blood Transfusion (ISBT). The two most important blood group systems are ABO blood group system, ABO and Rh blood group system, Rh; they determine someone's blood type (A, B, AB, and O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), but they can also have insertions and deletions of up to several thousand base pairs. Most alleles observed result in little or no change in the function or amount of the gene product(s) they code or regulate for. However, sometimes different alleles can result in different observable phenotypic traits, such as different pigmentation. A notable example of this is Gregor Mendel's discovery that the white and purple flower colors in pea plants were the result of a single gene with two alleles. Nearly all multicellular organisms have two sets of chromosomes at some point in their biological life cycle; that is, they are diploid. For a given locus, if the two chromosomes contain the same allele, they, and the organism, are homozygous with re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolysis
Hemolysis or haemolysis (), also known by #Nomenclature, several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo or in vitro. One cause of hemolysis is the action of hemolysins, toxins that are produced by certain pathogenic bacteria or Fungus, fungi. Another cause is intense physical exercise. Hemolysins damage the red blood cell's cytoplasmic membrane, causing lysis and eventually cell death. Etymology From hemo- + -lysis, from Ancient Greek (, 'blood') + , 'loosening'). Inside the body Hemolysis inside the body can be caused by a large number of medical conditions, including some parasites (''e.g.'', ''Plasmodium''), some autoimmune disorders (''e.g.'', autoimmune haemolytic anaemia, drug-induced hemolytic anemia, atypical hemolytic uremic syndrome (aHUS)), some genetic disorders (''e.g.'', Sickle-cell disease or G6PD deficiency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
