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Hemoglobin A
Hemoglobin A (HbA), also known as adult hemoglobin, hemoglobin A1 or α2β2, is the most common human hemoglobin tetramer, accounting for over 97% of the total red blood cell hemoglobin. Hemoglobin is an oxygen-binding protein, found in Red blood cell, erythrocytes, which transports oxygen from the lungs to the tissues. Hemoglobin A is the most common adult form of hemoglobin and exists as a tetramer containing two alpha subunits and two beta subunits (α2β2). Hemoglobin A2 (HbA2) is a less common adult form of hemoglobin and is composed of two alpha and two delta-globin subunits. This hemoglobin makes up 1-3% of hemoglobin in adults. Structure and function Hemoglobin A (HbA) is the most common adult form of hemoglobin and exists as a tetramer containing two alpha subunits and two beta subunits (α2β2). Each subunit contains a heme group that diatomic oxygen (O2) molecules can bind to. In addition to oxygen, subunit assembly and quaternary structure are known to play importa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoporphyrin IX
Protoporphyrin IX is an organic compound, classified as a porphyrin, that plays an important role in living organisms as a precursor to other critical compounds like heme (hemoglobin) and chlorophyll. It is a deeply colored solid that is not soluble in water. The name is often abbreviated as PPIX. Protoporphyrin IX contains a porphine core, a tetrapyrrole macrocycle with a marked aromatic character. Protoporphyrin IX is essentially planar, except for the N-H bonds that are bent out of the plane of the rings, in opposite (trans) directions. Nomenclature The general term protoporphyrin refers to porphine derivatives that have the outer hydrogen atoms in the four pyrrole rings replaced by other functional groups. The prefix proto often means 'first' in science nomenclature (such as carbon protoxide), hence Hans Fischer is thought to have coined the name protoporphyrin as the first class of porphyrins. Fischer described iron-deprived heme becoming the "proto-" porphyrin, partic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-thalassemia
Alpha-thalassemia (α-thalassemia, α-thalassaemia) is an inherited blood disorder and a form of thalassemia. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Symptoms depend on the extent to which hemoglobin is deficient, and include anemia, pallor, tiredness, enlargement of the spleen, iron overload, abnormal bone structure, jaundice, and gallstones. In severe cases death ensues, often in infancy, or death of the unborn fetus. The disease is characterised by reduced production of the alpha-globin component of hemoglobin, caused by inherited mutations affecting the genes ''HBA1'' and ''HBA2.'' This causes reduced levels of hemoglobin leading to anemia, while the accumulation of surplus beta-globin, the other structural component of hemoglobin, damages red blood cells and shortens their life. Diagnosis is by checking the medical history of near relatives, microscopi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haematopoiesis
Haematopoiesis (; ; also hematopoiesis in American English, sometimes h(a)emopoiesis) is the formation of blood cellular components. All cellular blood components are derived from haematopoietic stem cells. In a healthy adult human, roughly ten billion () to a hundred billion () new blood cells are produced per day, in order to maintain steady state levels in the peripheral circulation.Semester 4 medical lectures at Uppsala University 2008 by Leif Jansson Process Haematopoietic stem cells (HSCs) Haematopoietic stem cells (HSCs) reside in the medulla of the bone ( bone marrow) and have the unique ability to give rise to all of the different mature blood cell types and tissues. HSCs are self-renewing cells: when they differentiate, at least some of their daughter cells remain as HSCs so the pool of stem cells is not depleted. This phenomenon is called asymmetric division. The other daughters of HSCs ( myeloid and lymphoid progenitor cells) can follow any of the other diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassemia
Thalassemias are a group of Genetic disorder, inherited blood disorders that manifest as the production of reduced hemoglobin. Symptoms depend on the type of thalassemia and can vary from none to severe, including death. Often there is mild to severe anemia (low red blood cells or hemoglobin) as thalassemia can affect the production of red blood cells and also affect how long the red blood cells live. Symptoms include fatigue (medical), tiredness, pallor, bone problems, an splenomegaly, enlarged spleen, jaundice, pulmonary hypertension, and dark urine. A child's growth and development may be slower than normal. Thalassemias are genetic disorders. Alpha thalassemia is caused by deficient production of the Hemoglobin subunit alpha, alpha globin component of hemoglobin, while beta thalassemia is a deficiency in the Hemoglobin subunit beta, beta globin component. The severity of alpha and beta thalassemia depends on how many of the four genes for alpha globin or two genes for beta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sickle Cell Disease
Sickle cell disease (SCD), also simply called sickle cell, is a group of inherited Hemoglobinopathy, haemoglobin-related blood disorders. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to the red blood cells adopting an abnormal sickle-like shape under certain circumstances; with this shape, they are unable to deform as they pass through Capillary, capillaries, causing blockages. Problems in sickle cell disease typically begin around 5 to 6 months of age. A number of health problems may develop, such as attacks of pain (known as a sickle cell crisis) in joints, anemia, swelling in the hands and feet, bacterial infections, dizziness and stroke. The probability of severe symptoms, including long-term pain, increases with age. Without treatment, people with SCD rarely reach adulthood but with good healthcare, median life expectancy is between 58 and 66 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemoglobinopathy
Hemoglobinopathy is the medical term for a group of inherited blood disorders involving the hemoglobin, the major protein of red blood cells. They are generally single-gene disorders and, in most cases, they are inherited as Autosome, autosomal Recessive disorders, recessive traits. There are two main groups: abnormal structural hemoglobin variants caused by mutations in the hemoglobin genes, and the thalassemias, which are caused by an underproduction of otherwise normal hemoglobin molecules. The main structural hemoglobin variants are HbS, HbE and HbC. The main types of thalassemia are alpha-thalassemia and beta thalassemia. Hemoglobin functions Hemoglobin is a protein containing ferrous, iron that facilitates the transportation of oxygen in Red blood cell, red blood cells. Hemoglobin in the blood carries oxygen from the Lung, lungs to the other tissues of the body, where it releases the oxygen to enable aerobic respiration which powers the metabolism. Normal levels of hemoglob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication ( translesion synthesis). Mutations may also result from substitution, insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics ( phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutati ... [...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] |
Chromosome 11
Chromosome 11 is one of the 23 pairs of chromosomes in humans. Humans normally have two copies of this chromosome. Chromosome 11 spans about 135 million base pairs (the building material of DNA) and represents between 4 and 4.5 percent of the total DNA in cells. The shorter arm (p arm) is termed 11p while the longer arm (q arm) is 11q. At about 21.5 genes per megabase, chromosome 11 is one of the most gene-rich, and disease-rich, chromosomes in the human genome. More than 40% of the 856 olfactory receptor genes in the human genome are located in 28 single-gene and multi-gene clusters along the chromosome. Gene Number of genes The following are some of the gene count estimates of human chromosome 11. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ( CCDS) takes an extremely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 16
Chromosome 16 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 16 spans about 90 million base pairs (the building material of DNA) and represents just under 3% of the total DNA in cells. Genes Number of genes The following are some of the gene count estimates of human chromosome 16. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ( CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. Gene list The following is a partial list of genes on human chromosome 16. For complete list, see the link in the infobox on the right. Diseases and disorders *Attention deficit hyperactivity disorder (ADHD) *Asperger synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
