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Hyperphenylalanemia
Hyperphenylalaninemia is a medical condition characterized by mildly or strongly elevated concentrations of the amino acid phenylalanine in the blood. Phenylketonuria (PKU) can result in severe hyperphenylalaninemia. Phenylalanine concentrations ( he are routinely screened in newborns by the neonatal heel prick (Guthrie test), which takes a few drops of blood from the heel of the infant. Standard heconcentrations in unaffected persons are about 60µM: heconcentrations in persons with untreated phenylketonuria may be many times that (600µM to 2400µM), which indicate that the child is at risk for severe intellectual disability. Phenylketonuria is classed as an autosomal recessive condition: in heterozygous form, heshows a moderate elevation, perhaps two-fold over that of unaffected homozygotes, which is classified as hyperphenylalaninemia ('' hyper-'' + ''phenylalanine'' + '' -emia'' = high hein blood). Symptoms and signs The coloration of the skin, hair, and eyes is differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated PKU may have heart problems, a small head, and low birth weight. Phenylketonuria is an inherited genetic disorder. It is due to mutations in the '' PAH'' gene, which results in low levels of the enzyme phenylalanine hydroxylase. This results in the buildup of dietary phenylalanine to potentially toxic levels. It is autosomal recessive, meaning that both copies of the gene must be mutated for the condition to develop. There are two main types, classic PKU and variant PKU, depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not have symptoms. Many countries have newborn screening programs for the disease. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Condition
A disease is a particular abnormal condition that negatively affects the structure or function (biology), function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that are associated with specific signs and symptoms. A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergy, allergies and autoimmune disorders. In humans, ''disease'' is often used more broadly to refer to any condition that causes pain, Abnormality (behavior), dysfunction, distress (medicine), distress, social problems, or death to the person affected, or similar problems for those in contact with the person. In this broader sense, it sometimes includes injury, injuries, disability, disabilities, #Disorder, disorders, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uterus is a hormone-responsive sex organ that contains glands in its lining that secrete uterine milk for embryonic nourishment. In the human, the lower end of the uterus, is a narrow part known as the isthmus that connects to the cervix, leading to the vagina. The upper end, the body of the uterus, is connected to the fallopian tubes, at the uterine horns, and the rounded part above the openings to the fallopian tubes is the fundus. The connection of the uterine cavity with a fallopian tube is called the uterotubal junction. The fertilized egg is carried to the uterus along the fallopian tube. It will have divided on its journey to form a blastocyst that will implant itself into the lining of the uterus – the endometrium, where it will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Greek ''tyrós'', meaning ''cheese'', as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a functional group or side chain. While tyrosine is generally classified as a Hydrophobe, hydrophobic amino acid, it is more hydrophilic than phenylalanine. It is Genetic code, encoded by the Genetic code#Codons, codons UAC and UAU in messenger RNA. Functions Aside from being a proteinogenic amino acid, tyrosine has a special role by virtue of the phenol functionality. It occurs in proteins that are part of signal transduction processes and functions as a receiver of phosphate groups that are transferred by way of protein kinases. Phosphorylation of the hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-hydroxytryptophan
5-Hydroxytryptophan (5-HTP), also known as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin. Uses 5-HTP is sold over the counter in the United States, Canada, Singapore, the Netherlands, and the United Kingdom as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under the trade names Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. A 2002 review concluded that although the data evaluated suggests that 5-HTP is more effective than placebo in the treatment of depression, the evidence was insufficient to be conclusive due to a lack of clinical data meeting the rigorous standards of the day. More and larger studies using current methodologies are needed to determine if 5-HTP is truly effective in treating depression. In small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptophan
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α- carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. It is essential in humans, meaning that the body cannot synthesize it and it must be obtained from the diet. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3. It is encoded by the codon UGG. Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38). Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Function Amino acids, including tryptophan, are used as building blocks in protein biosynthesis, and proteins are required to sustain life. Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Brain
The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the activities of the body, processing, integrating, and coordinating the information it receives from the sense organs, and making decisions as to the instructions sent to the rest of the body. The brain is contained in, and protected by, the skull bones of the head. The cerebrum, the largest part of the human brain, consists of two cerebral hemispheres. Each hemisphere has an inner core composed of white matter, and an outer surface – the cerebral cortex – composed of grey matter. The cortex has an outer layer, the neocortex, and an inner allocortex. The neocortex is made up of six neuronal layers, while the allocortex has three or four. Each hemisphere is conventionally divided into four lobes – the frontal, temporal, parietal, and occipital lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available and often require a small number of biosynthetic steps for conversion. Neurotransmitters are essential to the function of complex neural systems. The exact number of unique neurotransmitters in humans is unknown, but more than 100 have been identified. Common neurotransmitters include glutamate, GABA, acetylcholine, glycine and norepinephrine. Mechanism and cycle Synthes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxylation
In chemistry, hydroxylation can refer to: *(i) most commonly, hydroxylation describes a chemical process that introduces a hydroxyl group () into an organic compound. *(ii) the ''degree of hydroxylation'' refers to the number of OH groups in a molecule. The ''pattern of hydroxylation'' refers to the location of hydroxy groups on a molecule or material. Hydroxylation reactions Synthetic hydroxylations Installing hydroxyl groups into organic compounds can be effected by various metal catalysts. Many such catalysts are biomimetic, i.e. they are inspired by or intended to mimic enzymes such as cytochrome P450. Whereas many hydroxylations insert O atoms into bonds, some reactions ''add'' OH groups to unsaturated substrates. The Sharpless dihydroxylation is such a reaction: it converts alkenes into diols. The hydroxy groups are provided by hydrogen peroxide, which adds across the double bond of alkenes. Biological hydroxylation In biochemistry, hydroxylation reactions are often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthesis
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. This process often consists of metabolic pathways. Some of these biosynthetic pathways are located within a single cellular organelle, while others involve enzymes that are located within multiple cellular organelles. Examples of these biosynthetic pathways include the production of lipid membrane components and nucleotides. Biosynthesis is usually synonymous with anabolism. The prerequisite elements for biosynthesis include: precursor compounds, chemical energy (e.g. ATP), and catalytic enzymes which may require coenzymes (e.g.NADH, NADPH). These elements create monomers, the building blocks for macromolecules. Some important biological macromolecules include: proteins, which are composed of amino acid monomers joined via peptide bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahydrobiopterin
Tetrahydrobiopterin (BH4, THB), also known as sapropterin (INN), is a cofactor of the three aromatic amino acid hydroxylase enzymes, used in the degradation of amino acid phenylalanine and in the biosynthesis of the neurotransmitters serotonin (5-hydroxytryptamine, 5-HT), melatonin, dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline), and is a cofactor for the production of nitric oxide (NO) by the nitric oxide synthases. Chemically, its structure is that of a (dihydropteridine reductase) reduced pteridine derivative (quinonoid dihydrobiopterin). Medical use Tetrahydrobiopterin is available as a tablet for oral administration in the form of ''sapropterin dihydrochloride'' (BH4*2HCL). It was approved for use in the United States as a tablet in December 2007 and as a powder in December 2013. It was approved for use in the European Union in December 2008, Canada in April 2010, and Japan in July 2008. It is sold under the brand names Kuvan and Biopten. The typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the 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 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 are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
