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HEPPS (molecule)
HEPPS (EPPS) is a buffering agent used in biology and biochemistry. The pKa of HEPPS is 8.00. It is ones of Good's buffers. Research on mice with Alzheimer's disease-like amyloid beta plaques has shown that HEPPS can cause the plaques to break up, reversing some of the symptoms in the mice. HEPPS was reported to dissociate amyloid beta oligomers in patients' plasma samples enabling blood diagnosis of Alzheimer's disease. See also * CAPSO * CHES * HEPES HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) is a zwitterionic sulfonic acid buffering agent. It is one of the twenty Good's buffers. HEPES is widely used in cell culture, largely because it is better at maintaining physiological pH ... References Buffer solutions Sulfonic acids Piperazines Primary alcohols {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffering Agent
A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean. Principles of buffering Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−: When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, History of life, origin, evolution, and distribution of life. Central to biology are five fundamental themes: the cell (biology), cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation for sustaining life processes, and the maintenance of internal stability (homeostasis). Biology examines life across multiple biological organisation, levels of organization, from molecules and cells to organisms, populations, and ecosystems. Subdisciplines include molecular biology, physiology, ecology, evolutionary biology, developmental biology, and systematics, among others. Each of these fields applies a range of methods to investigate biological phenomena, including scientific method, observation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemistry
Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all List of life sciences, areas of the life sciences are being uncovered and developed through biochemical methodology and research.#Voet, Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis that allows biomolecule, biological molecules to give rise to the processes that occur within living Cell (biology), cells and between cells,#Karp, Karp (2009), p. 2. in turn relating greatly to the understanding of tissue (biology), tissues and organ (anatomy), organs as well as organism structure and function.#Miller, Miller (2012). p. 62. Biochemistry is closely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Good's Buffers
Good's buffers (also Good buffers) are twenty buffering agents for biochemistry, biochemical and biology, biological research selected and described by Norman Good and colleagues during 1966–1980. Most of the buffers were new zwitterionic compounds prepared and tested by Good and coworkers for the first time, though some (MES (buffer), MES, ADA (buffer), ADA, BES, Bicine) were known compounds previously overlooked by biologists. Before Good's work, few hydrogen ion buffers between pH 6 and 8 had been accessible to biologists, and very inappropriate, toxic, reactive and inefficient buffers had often been used. Many Good's buffers became and remain crucial tools in modern biological laboratories. Selection criteria Good sought to identify buffering compounds which met several criteria likely to be of value in biological research. #: Because most biological reactions take place near-neutral pH between 6 and 8, ideal buffers would have values in this region to provide maximum buffer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer's Disease
Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the average life expectancy following diagnosis is three to twelve years. The causes of Alzheimer's disease remain poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an allele of apolipoprotein E. Other risk factors include a history of head injury, clinical depression, and high blood pressure. The progression of the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyloid Beta
Amyloid beta (Aβ, Abeta or beta-amyloid) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid-beta precursor protein (APP), which is cleaved by Beta-secretase 1, beta secretase and gamma secretase to yield Aβ in a cholesterol-dependent process and substrate presentation. Both neurons and oligodendrocytes produce and release Aβ in the brain, contributing to formation of amyloid plaques. Aβ molecules can aggregate to form flexible soluble oligomers which may exist in several forms. It is now believed that certain misfolded oligomers (known as "seeds") can induce other Aβ molecules to also take the misfolded oligomeric form, leading to a chain reaction akin to a prion infection. The oligomers are toxic to nerve cells. The other protein implicated in Alzheimer's disease, tau protein, also forms such prion-like misfolded oligomers, and there is some ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical & Engineering News
''Chemical & Engineering News'' (''C&EN'') is a weekly news magazine published by the American Chemical Society (ACS), providing professional and technical news and analysis in the fields of chemistry and chemical engineering.C&EN Magazine Website Chemical and Engineering News, October 12, 2009, accessed October 12, 2009 It includes information on recent news and research in these fields, career and employment information, business and industry news, government and policy news, funding in these fields, and special reports. The magazine is available to all members of the American Chemical Society. The ACS also publishes ''C&EN Global Enterprise'' (), an online resource that republishes articles from ''C&EN'' for easier online access to content. History The magazine was established in 1923,[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAPSO
CAPS is the common name for 3-(Cyclohexylamino)-1-propanesulfonic acid, a chemical used as buffering agent in biochemistry Biochemistry, or biological chemistry, is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, a .... The similar substance ''N''-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid (CAPSO) is also used as buffering agent in biochemistry. Its useful pH range is 9.7-11.1. See also * CHES * Good's buffers § List of Good's buffers References Buffer solutions Sulfonic acids {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CHES (buffer)
CHES (''N''-cyclohexyl-2-aminoethanesulfonic acid) is a buffering agent. CHES buffers have a useful range of pH 8.6–10. It typically appears as a white crystalline powder. Effect of impurities Commercial prep of CHES (and other sulfonylethyl buffers like MES, BES, and PIPES Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circu ...) can contain a contaminant oligo(vinylsulfonic acid) (OVS), which is a polyanionic mimic of RNA, and can be a potent ( pM) inhibitor of RNA binding proteins and enzymes. References External links * Buffer solutions Sulfonic acids {{OrganicAcid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HEPES
HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) is a zwitterionic sulfonic acid buffering agent. It is one of the twenty Good's buffers. HEPES is widely used in cell culture, largely because it is better at maintaining physiological pH despite changes in carbon dioxide concentration (produced by aerobic respiration) when compared to bicarbonate buffers, which are also commonly used in cell culture. Lepe-Zuniga ''et al.'' reported an unwanted photochemical process wherein HEPES catalyzes a reaction with riboflavin when exposed to ambient light to produce hydrogen peroxide. This is not a problem in bicarbonate-based cell culture buffers. It is therefore strongly advised to keep solutions containing both HEPES and riboflavin in darkness as much as possible to prevent oxidation. HEPES has the following characteristics: * p''K''a1 (25 °C) = 3 * p''K''a2 (25 °C) = 7.5 * Useful pH range = 2.5 to 3.5 or 6.8 to 8.2 HEPES has negligible metal ion binding, making ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Solutions
A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean. Principles of buffering Buffer solutions resist pH change because of a chemical equilibrium between the weak acid HA and its conjugate base A−: When some strong acid is added to an equilibrium mixture of the weak acid and its conjugate base, hydrogen ions (H+) are added, and the equilibrium is shifted to the left, in accordance with Le Chatelier's principle. Because of this, the hydrogen ion concentration increases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonic Acids
In organic chemistry, sulfonic acid (or sulphonic acid) refers to a member of the class of organosulfur compounds with the general formula , where R is an organic alkyl or aryl group and the group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound (with the organic substituent replaced by hydrogen) is the parent sulfonic acid, , a tautomer of sulfurous acid, . Salt (chemistry), Salts or esters of sulfonic acids are called sulfonates. Preparation Aryl sulfonic acids are produced by the process of sulfonation. Usually the sulfonating agent is sulfur trioxide. A large scale application of this method is the production of alkylbenzenesulfonic acids: : In this reaction, sulfur trioxide is an electrophile and the arene is the nucleophile. The reaction is an example of electrophilic aromatic substitution. In a related process, carboxyli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
