|
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 Ches may refer to: * Assata Shakur (married name Joanne Chesimard), nickname * CHES (buffer) *William Cheswick ("Ches") a computer security and networking researcher See also *Chez (other) *Chess Chess is a board game for two playe ... * HEPES References Buffer solutions Sulfonic acids Piperazines Primary alcohols {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffering Agent
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments. Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations.Based on definition from: Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use t ... [...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 areas of the life sciences are being uncovered and developed through biochemical methodology and research.Voet (2005), p. 3. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells, Karp (2009), p. 2. in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function. Miller (2012). p. 62. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Good's Buffers
Good's buffers (also Good buffers) are twenty buffering agents for biochemical and 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, 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 buffering capacity there. #Solubility: For ease in h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer's Disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term memory, remembering recent events. As the disease advances, symptoms can include primary progressive aphasia, problems with language, Orientation (mental), disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and challenging behaviour, 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 typical life expectancy following diagnosis is three to nine years. The cause of Alzheimer's disease is poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an alle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyloid Beta
Amyloid beta (Aβ or Abeta) 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 precursor protein (APP), which is cleaved by beta secretase and gamma secretase to yield Aβ in a cholesterol-dependent process and substrate presentation. 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 evidence that misfolded Aβ can induce tau to misfold. A study has suggested that APP and its amyloid potential is of ancient origins, dating as far ba ... [...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, 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. History The magazine was established in 1923,C&EN- Happy Birthday to Us, accessed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAPSO
CAPS is the common name for ''N''-cyclohexyl-3-aminopropanesulfonic acid, a chemical used as buffering agent in biochemistry. 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 Ches may refer to: * Assata Shakur (married name Joanne Chesimard), nickname * CHES (buffer) *William Cheswick ("Ches") a computer security and networking researcher See also *Chez (other) *Chess Chess is a board game for two playe ... * 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)
''N''-Cyclohexyl-2-aminoethanesulfonic acid, also known as CHES, is a buffering agent A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is .... Typically appears as a white crystalline powder. CHES buffers have a useful range of pH 8.6–10. External links * {{organic-compound-stub Buffer solutions Sulfonic acids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HEPES
HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) is a zwitterionic sulfonic acid buffering agent; 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 when exposed to ambient light produces hydrogen peroxide, which is not a problem in bicarbonate-based cell culture buffers. It is therefore strongly advised to keep HEPES-containing solutions 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 it a good choice as a buffer for enzymes which might be inhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buffer Solutions
A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. 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 ... [...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, . 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: :RC6H5 + SO3 -> RC6H4SO3H In this reaction, sulfur trioxide is an electrophile and the arene is the nucleophile. The reaction is an example of electrophilic aromatic substitution. Alkylsul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
