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Biochemistry环境化学环境化学是研究化学物质在环境中迁移、转化、降解规律，研究化学物质在环境中的作用的学科。它不应与绿色化学，即探求如何减少潜在的污染源头的学科搞混。它可以定义为研究源头、反应、物质运动、作用效果、以及化学元素在空气、土壤和水利环境的生存和人类活动对其的影响。 环境化学是在各个学科之间的科学，包括大气、水生以及土壤化学，也减轻在分析化学和使环境与其他有关科学的部分发生关系起到很大作用。 环境化学重要的研究成果是发现DDT在环境中很难降解，并会在通过食物链在动物体内蓄积，导致在全世界禁止生产、使用DDT；另外发现氟里昂在环境中不降解，会消耗、破坏臭氧层，导致对氟里昂使用、生产的限制和无氟冰箱的出现， 环境化学家利用化学和各种环境科学的一系列概念来帮助他们研究环境中化学物质的变化。 化学中重要的一般概念包括理解化学反应和方程式、溶液、单位、抽样和分析技术。
Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity and biological activity on these. Environmental chemistry is an interdisciplinary science that includes atmospheric, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to environmental and other areas of science. Environmental chemistry involves first understanding how the uncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on the environment through the release of chemicals. Environmental chemists draw traditional chemical concepts as well as sampling and analytical techniques.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 歧化反应（又称异化反应、不均化反应），是一种元素在同一反应中同时被氧化和被还原的一种自身氧化还原反应。在歧化反应中，反应物中处于过度氧化态的元素会转变为两种不同的化合物，其中一种的氧化数上升，另一种则下降。与其相反的逆反应称为归中反应。 广义来说，歧化反应也可指两个相同分子转变为两种不同产物的去对称反应，例如： 2 A ⟶ A ′ + A ″ {\displaystyle {\ce {2A -> A' + A''}}} 此定义不局限于氧化还原反应，例如在自偶电离反应中，反应后原子的氧化数不变。
In chemistry, disproportionation, sometimes called dismutation (the French word), is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as symproportionation. More generally, the term can be applied to any desymmetrizing reaction where two molecules of one type react to give one each of two different types: 2 A → A' + A" This expanded definition is not limited to redox reactions, but also includes some molecular autoionization reactions, such as the self-ionization of water.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 势能面，表示某一微观体系的势能和相关参数（通常为原子坐标）之间的函数关系，是势能函数的图像。势能面用一个或更多的坐标去表示，当用一个坐标去表示时，势能面通常被称为“势能曲线”。 势能面概念被用在物理以及化学领域, 尤其是它们的理论研究分支。 势能面可以被用来从理论层面理解由原子组成的物质的性质, 例如：搜寻分子的最低能量构形或者计算化学反应速率。 势能面类似于对地形的描述：对于一个有两个自由度的体系（例如：一个键长、一个键角），体系的势能可以类比为地形的高度，两个自由度可以类比为描述某位置的坐标。通过这样的描述，体系势能随坐标的变化可以很直观地被表示出来。 体系总势能与原子在空间的排布有关，是原子坐标等参数的函数，可以用一条曲线或一个多维表面表示。狭义的讲，将参数多于一个的势能图像叫做“(超)势能面”，而一维势能函数的图像称为“势能曲线”。势能面的多项式表面形式与它们在势能理论里的应用，有着自然的对应关系，而这种关系牵涉到对这些表面相互之间的调和函数。
A potential energy surface (PES) or energy landscape describes the energy of a system, especially a collection of atoms, in terms of certain parameters, normally the positions of the atoms. The surface might define the energy as a function of one or more coordinates; if there is only one coordinate, the surface is called a potential energy curve or energy profile. An example is the Morse/Long-range potential. It is helpful to use the analogy of a landscape: for a system with two degrees of freedom (e.g. two bond lengths), the value of the energy (analogy: the height of the land) is a function of two bond lengths (analogy: the coordinates of the position on the ground). The PES concept finds application in fields such as physics, chemistry and biochemistry, especially in the theoretical sub-branches of these subjects. It can be used to theoretically explore properties of structures composed of atoms, for example, finding the minimum energy shape of a molecule or computing the rates of a chemical reaction.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ N,N'-二环己基碳二亚胺（简称为DCC）是一个常用的脱水剂，化学式为C13H22N2，在多肽合成时尤其重要。
N,N′-Dicyclohexylcarbodiimide (DCC or DCCD) is an organic compound with the chemical formula (C6H11N)2C. It is a waxy white solid with a sweet odor. Its primary use is to couple amino acids during artificial peptide synthesis. The low melting point of this material allows it to be melted for easy handling. It is highly soluble in dichloromethane, tetrahydrofuran, acetonitrile and dimethylformamide, but insoluble in water.
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View content license ↗ N-乙基马来酰亚胺（英语：N-Ethylmaleimide，缩写NEM）是一种含氮有机化合物，化学式C6H7NO2，是马来酰亚胺的N-乙基取代物，带有酰亚胺官能团，其碳碳双键可以与硫醇反应，常用于修饰肽链上的半胱氨酸残基。
N-Ethylmaleimide (NEM) is an organic compound that is derived from maleic acid. It is an unstable substance that reacts rapidly with thiols and is commonly used to modify cysteine residues in proteins and peptides.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 埃尔曼试剂（5,5′-二硫代双(2-硝基苯甲酸)，DTNB）是一种有机化合物，可以用于样品中巯基的定量分析。它可由相应的硫酚经碘氧化制得。它和硫醇反应，分子中-S-S-键断裂，在中性或碱性条件下生成黄色的2-硝基-5-巯基苯甲酸根（TNB−）。 这个反应定量且迅速，每加入1 mol硫醇时，会释放1 mol的TNB。TNB2−可以通过分光光度法测定其在412 nm处的吸收峰。
Ellman's reagent (5,5′-dithiobis-(2-nitrobenzoic acid) or DTNB) is a colorogenic chemical used to quantify the number or concentration of thiol groups in a sample. It was developed by George L. Ellman.
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View content license ↗ N,N'-二异丙基碳二亚胺是一种用于肽合成的碳二亚胺。因为N,N'-二异丙基碳二亚胺在常温常压下作液体，它比常用的蜡状固体N, N′-二环己基碳二亚胺更容易处理。此外，N,N'-二异丙基碳二亚胺在许多化学反应中生成的N,N'-二异丙基脲可溶于大多数有机溶剂，这一特性有助于产物的后处理。
N,N′-Diisopropylcarbodiimide is a carbodiimide used in peptide synthesis. As a liquid, it is easier to handle than the commonly used N,N′-dicyclohexylcarbodiimide, a waxy solid. In addition, N,N′-diisopropylurea, its byproduct in many chemical reactions, is soluble in most organic solvents, a property that facilitates work-up.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 能量稳态（英文：Energy homeostasis）或能量平衡的稳态控制，在生物学中，是一个生物过程，涉及食物摄入（能量流入）和能量消耗（能量流出）的协调稳态调节。人脑，尤其是下丘脑会通过整合许多传递能量平衡信息的生化信号，在调节能量稳态和产生饥饿感方面发挥着核心作用。50%的葡萄糖代谢能量立即转化为热量。 能量稳态是生物能量学的一个重要方面。
In biology, energy homeostasis, or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation of food intake (energy inflow) and energy expenditure (energy outflow). The human brain, particularly the hypothalamus, plays a central role in regulating energy homeostasis and generating the sense of hunger by integrating a number of biochemical signals that transmit information about energy balance. Fifty percent of the energy from glucose metabolism is immediately converted to heat. Energy homeostasis is an important aspect of bioenergetics.
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View content license ↗ 艾默生效应（英语：Emerson effect），绿色植物在红光（波长660nm）和红外线（波长>680nm）分别照射下，各有各自的光合作用效率。但植物在这二种光同时照射下，它们的光合作用效率远大于这二种光单独照射时的光合作用效率的总和。这种现象称为艾默生效应，该现象是罗伯特·艾默生于1957年发现，故以他的名字命名。 艾默生根据他发现的效应，做出结论（假设）；植物的叶绿体存在二种化学反应；一种由红光驱动；另一种由红外线驱动；它们共同使效率增加，把光转换成植物能吸收的能量。这种假设已得到实验的证实。
The Emerson effect is the increase in the rate of photosynthesis after chloroplasts are exposed to light of wavelength less than 680 nm (deep red spectrum) and more than 680 nm (far red spectrum). When simultaneously exposed to light of both wavelengths, the rate of photosynthesis is higher than the sum of the red light and far red light photosynthesis rates. The effect was early evidence that two photosystems, processing different wavelengths, cooperate in photosynthesis.
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View content license ↗ β-半乳糖苷酶（英语：β-galactosidase）是一种水解酶，催化β-半乳糖苷水解成单糖。使β-半乳糖苷酶作用的底物包括神经节苷脂GM1、乳糖苷、乳糖、各种糖蛋白。
β-Galactosidase (EC 3.2.1.23, beta-gal or β-gal; systematic name β-D-galactoside galactohydrolase) is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides. It is sometimes loosely referred to as lactase, but that name is technically reserved for mammalian digestive enzymes that break down lactose specifically. β-gal digests many other additional β-galactosides, which are carbohydrates containing galactose where the glycosidic bond lies above the galactose molecule. Substrates of different β-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins.
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View content license ↗ ATP合成酶，又称三磷酸腺苷合成酶或ATP合酶，在这里并特指F类的FoF1ATP合酶（F Type FoF1 ATP Synthase）。它利用呼吸链产生的质子的电化学势能，通过改变蛋白质的结构来进行三磷酸腺苷(ATP)的合成。ATP是大多数生物体中细胞最常用的“能量通货”。 它由二磷酸腺苷（ADP）和无机磷酸盐（Pi）形成。 ATP合酶催化的总体反应为： ADP + Pi + H+out ⇌ ATP + H2O + H+in ATP合酶由两个主要的亚基Fo和F1组成，它们具有允许ATP产生的旋转运动机制。
ATP synthase is an enzyme that catalyzes the formation of the energy storage molecule adenosine triphosphate (ATP) using adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP synthase is a molecular machine. The overall reaction catalyzed by ATP synthase is: ADP + Pi + 2H+out ⇌ ATP + H2O + 2H+in ATP synthase lies across a cellular membrane and forms an aperture that protons can cross from areas of high concentration to areas of low concentration, imparting energy for the synthesis of ATP. This electrochemical gradient is generated by the electron transport chain and allows cells to store energy in ATP for later use. In prokaryotic cells ATP synthase lies across the plasma membrane, while in eukaryotic cells it lies across the inner mitochondrial membrane. Organisms capable of photosynthesis also have ATP synthase across the thylakoid membrane, which in plants is located in the chloroplast and in cyanobacteria is located in the cytoplasm. ATP synthase is present in all organisms studied.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 生物催化（英语：Biocatalysis）是使用天然催化剂酶，对有机化合物进行的化学转化。这种反应过程又被称为“生物转化”。离体的酶和活细胞中的酶都可以参与到这一活动中。
Biocatalysis refers to the use of living (biological) systems or their parts to speed up (catalyze) chemical reactions. In biocatalytic processes, natural catalysts, such as enzymes, perform chemical transformations on organic compounds. Both enzymes that have been more or less isolated and enzymes still residing inside living cells are employed for this task. Modern biotechnology, specifically directed evolution, has made the production of modified or non-natural enzymes possible. This has enabled the development of enzymes that can catalyze novel small molecule transformations that may be difficult or impossible using classical synthetic organic chemistry. Utilizing natural or modified enzymes to perform organic synthesis is termed chemoenzymatic synthesis; the reactions performed by the enzyme are classified as chemoenzymatic reactions.
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View content license ↗ ASH1L（亦称为huASH1、ASH1、ASH1L1、ASH1-like或KMT2H）化学式为：C14553H23487O4453N4241S115是一个由位于1号染色体长臂22带的ASH1L基因所编码的组蛋白-赖氨酸N-甲基转移酶。ASH1L是果蝇属Ash1（英语：absent, small, or homeotic discs 1）基因的人类同源物。
ASH1L (also called huASH1, ASH1, ASH1L1, ASH1-like, or KMT2H) is a histone-lysine N-methyltransferase enzyme encoded by the ASH1L gene located at chromosomal band 1q22. ASH1L is the human homolog of Drosophila Ash1 (absent, small, or homeotic-like).
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View content license ↗ C-5甾醇去饱和酶（英语：C-5 sterol desaturase，或称为甾醇C-5去饱和酶 sterol C-5 desaturase，缩写C5SD）是广泛存在于真核生物体内，参与类固醇生成的酶，依赖NADH将类固醇底物的5、6号碳原子上的氢脱去，生成带碳碳双键的产物。在人体中，C-5去饱和酶将7-胆甾烯醇脱氢生成7-脱氢胆固醇，最后转化为胆固醇。在真菌酿酒酵母（Saccharomyces cerevisiae）中，C5SD催化表甾醇脱氢生成5-脱氢表甾醇，最后转化为麦角固醇，在一些植物中，C5SD参与油菜素类固醇、谷固醇的合成。
C-5 sterol desaturase (also known as sterol C-5 desaturase and C5SD) is an enzyme that is highly conserved among eukaryotes and catalyzes the dehydrogenation of a C-5(6) bond in a sterol intermediate compound as a step in the biosynthesis of major sterols. The precise structure of the enzyme's substrate varies by species. For example, the human C-5 sterol desaturase (also known as lathosterol oxidase) oxidizes lathosterol, while its ortholog ERG3 in the yeast Saccharomyces cerevisiae oxidizes episterol.
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View content license ↗ 固定化酶（immobilized enzyme）是一种酶工程的常见技术。将水溶性酶经过物理或化学方法改造，然后固定到特定载体上，成为水不溶性，能反复连续进行有效催化反应，这样的酶称为固定化酶。这种技术可以使得酶对于pH或者温度的抗逆性增加。这种技术也使得酶在反应中得以被固定，因此可以轻易地与反应物或产物中分离，从而多次使用。这种高效的技术在工业化酶促反应中被广泛应用。固定化酶的其中一种技术也被称作全细胞固定化技术。
An immobilized enzyme is an enzyme, with restricted mobility, attached to an inert, insoluble material—such as calcium alginate (produced by reacting a mixture of sodium alginate solution and enzyme solution with calcium chloride). This can provide increased resistance to changes in conditions such as pH or temperature. It also lets enzymes be held in place throughout the reaction, following which they are easily separated from the products and may be used again - a far more efficient process and so is widely used in industry for enzyme catalysed reactions. An alternative to enzyme immobilization is whole cell immobilization. Immobilized enzymes are easily to be handled, simply separated from their products, and can be reused. Enzymes are bio-catalysts which play an essential role in the enhancement of chemical reactions in cells without being persistently modified, wasted, nor resulting in the loss of equilibrium of chemical reactions.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 组胺N-甲基转移酶（英语：Histamine N-methyltransferase；HMT、HNMT）是涉及到组胺代谢的两种酶中的一种。另外一个是胺氧化酶。组胺N-甲基转移酶在S-腺苷甲硫氨酸（SAM）存在的情况下催化组胺甲基化形成N-甲基组胺。此酶存在于大多数身体组织当中但不存在于体液之中。组胺N-甲基转移酶被单个基因编码，其被编码于2号染色体上。
Histamine N-methyltransferase (HNMT) is a protein encoded by the HNMT gene in humans. It belongs to the methyltransferases superfamily of enzymes and plays a role in the inactivation of histamine, a biomolecule that is involved in various physiological processes. Methyltransferases are present in every life form including archaeans, with 230 families of methyltransferases found across species. Specifically, HNMT transfers a methyl (-CH3) group from S-adenosyl-L-methionine (SAM-e) to histamine, forming an inactive metabolite called Nτ-methylhistamine, in a chemical reaction called Nτ-methylation. In mammals, HNMT and diamine oxidase (DAO) are the only two enzymes responsible for histamine metabolism; unlike DAO, HNMT is present within the central nervous system (CNS), where it governs histaminergic neurotransmission, that is a process where histamine acts as a messenger molecule between the neurons—nerve cells—in the brain. By degrading and regulating levels of histamine within the CNS, HNMT supports neural pathways related to arousal, appetite regulation, and sleep-wake cycles.
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View content license ↗ 在分子生物学领域，SWI/SNF（英语：SWItch/Sucrose NonFermentable）是同时存在于真核生物及原核生物中的一种核小体重塑复合物。简而言之，它们是一群与重塑DNA包装方式有关的蛋白质。SWI/SNF由多种蛋白构成，这些蛋白往往是SWI及SNF基因（SWI1、SWI2/SNF2、SWI3、SWI5、SWI6）的产物以及一些其它多肽。SWI/SNF受DNA刺激后表现出ATP酶活性，利用ATP破坏并重塑核小体的组蛋白和DNA之间相互作用的稳定性，不过这种结构改变的精确性质仍未明确。 人体中与SWI/SNF相似的蛋白是BAF（与SWI/SNF-A相似）和PBAF（与SWI/SNF-B相似）。BAF表示“BRG1或HRBM相关因子”，PBAF则表示“聚溴相关的BAF”。
In molecular biology, SWI/SNF (SWItch/Sucrose Non-Fermentable), is a subfamily of ATP-dependent chromatin remodeling complexes, which is found in eukaryotes. In other words, it is a group of proteins that associate to remodel the way DNA is packaged. This complex is composed of several proteins – products of the SWI and SNF genes (SWI1, SWI2/SNF2, SWI3, SWI5, SWI6), as well as other polypeptides. It possesses a DNA-stimulated ATPase activity that can destabilize histone-DNA interactions in reconstituted nucleosomes in an ATP-dependent manner, though the exact nature of this structural change is unknown. The SWI/SNF subfamily provides crucial nucleosome rearrangement, which is seen as ejection and/or sliding. The movement of nucleosomes provides easier access to the chromatin, enabling binding of specific transcription factors, and allowing genes to be activated or repressed. The human analogs of SWI/SNF are "BRG1- or BRM-associated factors", or BAF (SWI/SNF-A) and "Polybromo-associated BAF", which is also known as PBAF (SWI/SNF-B).
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 人工酶是指人工合成的具有酶活性位点的有机分子。 酶能够以高度的专一性和催化效率对化学反应进行催化，而酶的催化活性位点只是酶这样的大分子中的很小一部分。因此，可以通过人工合成小分子，包括结合底物的基团和进行催化的功能性基团，来模拟酶的活性位点。由于需要结合分子，因此人工酶是在宿主分子，如环糊精、冠醚、杯芳烃等环状分子的基础上进行设计的。 许多催化不同反应的人工酶已经被报道提高反应速率的倍数可达103；然而，其催化效率依然远低于天然的酶（通常可以提高反应速率至106倍）。人工酶研究领域中的开拓者是化学家Ronald Breslow。 纳米酶是具有酶类催化活性的功能纳米材料。作为新兴的人工模拟酶，纳米酶已被广泛探索用于各种应用，如生物传感、生物成像、肿瘤诊断和治疗、抗生物污垢。
An artificial enzyme, also known as a synthetic enzyme or a synzyme, is a synthetic organic molecule or ion that recreates one or more functions of a natural enzyme. These molecules aim to achieve catalysis with rates and selectivity comparable to those of naturally occurring enzymes. A nanozyme is a sub-type of artificial enzyme which however is classified into the group of nanomaterials. Current synzymes consist mainly of organic molecules tailored in such a way that they catalyse certain kinds of reactions. Like enzymes, they bind a transition state of a substrate in an active site, and like enzymes they generally obey Michaelis–Menten kinetics.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 类固醇生成酶类（英语：Steroidogenic enzymes）是指一大类涉及甾体激素生物合成与代谢的酶类。这些酶参与合成的甾体激素包括性激素类（雄激素、雌激素、孕激素）和肾上腺皮质激素类（糖皮质激素和盐皮质激素，以及由胆固醇生成的神经甾体。类固醇生成酶在涉及类固醇生成的组织，如睾丸、卵巢、肾上腺皮质里有很高的表达，但也存在于身体的其他组织。
Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis. They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and corticosteroids (glucocorticoids and mineralocorticoids), as well as neurosteroids, from cholesterol. Steroidogenic enzymes are most highly expressed in classical steroidogenic tissues, such as the testis, ovary, and adrenal cortex, but are also present in other tissues in the body.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 酮症是一种代谢状态，当体内的葡萄糖不足时，肝脏会将脂肪转换成脂肪酸与酮体，取代原本由葡萄糖负责的能量来源。当血中酮体的含量大于0.5mM，且有长时间的低血糖及低胰岛素含量，即为‘酮症’。 当肝脏中储存的肝糖用尽时，便会进行生酮作用(ketogenesis)，产生酮体；另外代谢中链甘油三酯亦会有酮体的产生。 身体主要利用的酮体为乙酰乙酸(acetoacetate)及β-羟基丁酸(β-hydroxybutyrate)，而酮体的调节主要由胰岛素及升糖素控制。大部分的细胞都可以用葡萄糖及酮体做为能量。在酮症的状态，身体会利用游离脂肪酸及糖质新生作为剩余的能量来源。 长期酮症可能由于禁食或生酮饮食导致，现今有些人会故意处于酮症状态，作为一些疾病的治疗方式，如糖尿病、顽固型癫痫。在一般糖解作用时，胰岛素会促进脂肪的储存及阻止脂肪从脂肪细胞释放；而在酮症状态下，脂肪细胞会释放脂肪并代谢之产生能量。因此，酮症被认为是一种脂肪消耗的模式。 酮症与酮酸中毒相似，但酮酸中毒是急性危及生命的状态，需要立即的医学治疗，而酮症可以是生理性的，在某些情况下(如抗药性癫痫)，酮症可能是对健康有益的。
Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low glucose availability. In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency. Ketoacidosis is most commonly the result of complete insulin deficiency in type 1 diabetes or late-stage type 2 diabetes. Ketone levels can be measured in blood, urine or breath and are generally between 0.5 and 3.0 millimolar (mM) in physiological ketosis, while ketoacidosis may cause blood concentrations greater than 10 mM. Trace levels of ketones are always present in the blood and increase when blood glucose reserves are low and the liver shifts from primarily metabolizing carbohydrates to metabolizing fatty acids.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 铁硫世界学说（英语：Iron–sulfur world theory），是由在慕尼黑的有化学学位的专利律师根特·瓦赫特绍泽从1988年到1992年期间发表一系列文章提出的生命起源和早期进化的假设，他提出早期生命可能在铁的硫化物矿物质的表面形成。该学说的发表获得哲学家卡尔·波普尔的鼓励和支持。它是通过现代生物化学结合化学实验的逆转而被开发的。 假说中的生命起源的基本思想可以概括为：用溶解的火山气体（例如一氧化碳、氨、硫化氢）加压和加热水流至100°C，再让水流从有催化性能过渡金属化合物固体（例如硫化铁、硫化镍）上流过，等待和定位催化金属肽的形成。如此合成有机分子，成为生命最早的起源。
The iron–sulfur world hypothesis is a set of proposals for the origin of life and the early evolution of life advanced in a series of articles between 1988 and 1992 by Günter Wächtershäuser, a Munich patent lawyer with a degree in chemistry, who had been encouraged and supported by philosopher Karl R. Popper to publish his ideas. The hypothesis proposes that early life may have formed on the surface of iron sulfide minerals, hence the name. It was developed by retrodiction (making a "prediction" about the past) from extant biochemistry (non-extinct, surviving biochemistry) in conjunction with chemical experiments.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 遗传性代谢缺陷（英语：Inborn error of metabolism）在新陈代谢过程中，除了制造出营养外，如果身体未能将食物其他部分成功代谢成为可以从排泄器官（如消化系统，泌尿系统及排汗系统、呼吸系统等）排出之废弃物，这些废弃物将遗留在身体器官里，最终会对身体产生不良后果，形成毒害。
Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances (substrates) into others (products). In most of the disorders, problems arise due to accumulation of substances which are toxic or interfere with normal function, or due to the effects of reduced ability to synthesize essential compounds. Inborn errors of metabolism are often referred to as congenital metabolic diseases or inherited metabolic disorders. Another term used to describe these disorders is "enzymopathies". This term was created following the study of biodynamic enzymology, a science based on the study of the enzymes and their products. Finally, inborn errors of metabolism were studied for the first time by British physician Archibald Garrod (1857–1936), in 1908. He is known for work that prefigured the "one gene–one enzyme" hypothesis, based on his studies on the nature and inheritance of alkaptonuria.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 烯醇（Enol）指的是双键碳上连有羟基的一类化合物，其（下图右）与羰基化合物（下图左）成互变异构： 通常在平衡中烯醇式占的很少。这是由于氧的电负性大于碳，因而碳氧双键更加稳定。 随着α氢的活泼性增大，失去氢后形成的碳负离子稳定性增大，烯醇式也能成为平衡中主要的存在形式。比如1,3-二羰基化合物中烯醇式的比例明显增加。类似的例子还可以是1,1,1-三氟-2,4-戊二酮。 酮式及烯醇式的含量和溶剂的极性也很有关系，非质子溶剂对烯醇式有利，因为可以帮助分子内氢键的形成。如乙酰乙酸乙酯的烯醇式含量在乙醇中为10%-13%，而在正己烷中为49%。 天然存在的维生素C即具有烯二醇的结构，因此维生素C具有酸性，又称为抗坏血酸。
In organic chemistry, enols are a type of functional group or intermediate in organic chemistry. Formally, enols are derivatives of vinyl alcohol, with a C=C−OH connectivity. The term enol is an abbreviation of alkenol, a portmanteau deriving from "-ene"/"alkene" and "-ol"/"alcohol". Keto–enol tautomerism refers to a chemical equilibrium between a "keto" form (a carbonyl, named for the common ketone case) and an enol. The tautomeric interconversion involves hydrogen atom movement and the reorganisation of bonding electrons. Many kinds of enols are known, but very few are stable compounds. However, deprotonation of organic carbonyls gives enolate anions, which are important in organic reaction strategies as a strong nucleophile.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 异戊烯基焦磷酸（Isopentenyl pyrophosphate，IPP）是甲羟戊酸途径和非甲羟戊酸途径的一个产物，属于类萜前体。异戊二烯焦磷酸与它的同分异构体二甲烯丙基焦磷酸（DMAPP）是许多萜和类萜的生物合成重要前体。
Isopentenyl pyrophosphate (IPP, isopentenyl diphosphate, or IDP) is an isoprenoid precursor. IPP is an intermediate in the classical, HMG-CoA reductase pathway (commonly called the mevalonate pathway) and in the non-mevalonate MEP pathway of isoprenoid precursor biosynthesis. Isoprenoid precursors such as IPP, and its isomer DMAPP, are used by organisms in the biosynthesis of terpenes and terpenoids.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 三磷酸尿苷（英语：uridine triphosphate, UTP）是一种嘧啶核苷酸，由碱基、尿嘧啶与核糖组成，另外还接有一个三磷酸于5'位置。UTP主要是作为RNA合成（转录）时的原料。
Uridine-5′-triphosphate (UTP) is a pyrimidine nucleoside triphosphate, consisting of the organic base uracil linked to the 1′ carbon of the ribose sugar, and esterified with tri-phosphoric acid at the 5′ position. Its main role is as substrate for the synthesis of RNA during transcription. UTP is the precursor for the production of CTP via CTP synthetase. UTP can be biosynthesized from UDP by nucleoside-diphosphate kinase after using the phosphate group from ATP. UDP + ATP ⇌ UTP + ADP; both UTP and ATP are energetically equal. The homologue in DNA is thymidine triphosphate (TTP or dTTP). UTP also has a deoxyribose form (dUTP).
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View content license ↗ 雄性化（英语：Virilization、masculinization）是两性异形发展时的生理发育过程，这个阶段产生的变化会使得雄性的身体变得与雌性不同。大部分雄性化都是由雄激素引起。“雄性化”一词在性别分化、新生儿发育和女性雄激素过量这三种语境下最常被提及。
Virilization or masculinization is the biological development of adult male characteristics in young males or females. Most of the changes of virilization are produced by androgens. Virilization is a medical term commonly used in three medical and biology of sex contexts: prenatal biological sexual differentiation, the postnatal changes of typical chromosomal male (46, XY) puberty, and excessive androgen effects in typical chromosomal females (46, XX). It is also the intended result of androgen replacement therapy in males with delayed puberty and low testosterone.
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View content license ↗ tau蛋白（tau proteins）或作τ蛋白、涛蛋白，化学式为：C3384H5471O1143N997S12，是一种广泛存在于神经元轴突与胞体中的微管相关细胞骨架蛋白。在正常生理情况下，tau蛋白多与微管蛋白相结合，有促进微管聚合和稳定的作用。术语“tau”是 tubulin associated unit（微管蛋白相关单位）的缩写。 tau蛋白属于一种低分子量微管相关蛋白，在中枢神经系统的神经元非常丰富而少见于其它细胞，但在中枢神经系统的星形胶质细胞和少突胶质细胞中表达量也很低。在病理状态下，tau蛋白呈过磷酸化，从微管上解离并变为不溶性，形成双螺旋状或直的神经原纤维（neurofibril），导致神经原纤维缠结（neurofibrillary tangles）形成，与神经系统病变（阿兹海默病）相关。 tau蛋白的多种蛋白异型体是由单个基因（人类基因组中为 MAPT，microtubule-associated protein tau，微管相关蛋白tau）mRNA的选择性剪接而形成的。1975年，它们由Marc Kirschner在普林斯顿大学的实验室中发现。
The tau proteins (abbreviated from tubulin associated unit) form a group of six highly soluble protein isoforms produced by alternative splicing from the gene MAPT (microtubule-associated protein tau). They have roles primarily in maintaining the stability of microtubules in axons and are abundant in the neurons of the central nervous system (CNS), where the cerebral cortex has the highest abundance. They are less common elsewhere but are also expressed at very low levels in CNS astrocytes and oligodendrocytes. Degeneration of the nervous system in forms of dementia such as Alzheimer's disease, frontotemporal dementia (FTD) disorders, and Parkinson's disease are associated with tau protein pathology, in which tau abnormally aggregates. The tau proteins were identified in 1975 as heat-stable proteins essential for microtubule assembly, and have since been characterized as intrinsically disordered proteins.
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Wikipedia contributors · Retrieved2026-10-04 · CC BY-SA 4.0. Introductions were extracted as plain text and shortened. Language versions may emphasize different aspects.For concept reference; consult the original standards for authoritative requirements.
View content license ↗ 视觉光转导（visual phototransduction）是视觉系统的光感受器将光能转变为电信号并传至视觉中枢的生物化学过程，属一种感觉转导。 通过视觉光转导过程，光在眼睛视网膜的视杆细胞、视锥细胞和内在光敏视网膜神经节细胞中转换为电信号。乔治·沃尔德（1906–1997）因阐明了这一机制而在1967年获得了诺贝尔奖。在而该机制也因此而被命名为“沃尔德视觉循环”。 视觉循环是光子在视网膜中经由一系列的生物化学反应而转化为电信号的过程。该过程通过一种被称为视蛋白的G蛋白偶联受体来触发，该受体包含发色团11-顺式视网醛。
Visual phototransduction is the sensory transduction process of the visual system by which light is detected by photoreceptor cells (rods and cones) in the vertebrate retina. A photon is absorbed by a retinal chromophore (each bound to an opsin), which initiates a signal cascade through several intermediate cells, then through the retinal ganglion cells (RGCs) comprising the optic nerve.
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View content license ↗ D-木糖是一种五碳的醛糖（戊糖、单糖），可被多种微生物催化代谢为有用的产物。 已知至少有四种木糖代谢的途径：1，氧化还原途径，存在于真核微生物中；2，异构酶途径，存在于某些原核生物中；3，Weimberg途径，一种原核生物的氧化途径；4，Dahms途径，原核生物的另一种氧化途径。
D-Xylose is a five-carbon aldose (pentose, monosaccharide) that can be catabolized or metabolized into useful products by a variety of organisms. There are at least four different pathways for the catabolism of D-xylose: An oxido-reductase pathway is present in eukaryotic microorganisms. Prokaryotes typically use an isomerase pathway, and two oxidative pathways, called Weimberg and Dahms pathways respectively, are also present in prokaryotic microorganisms.
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View content license ↗ 甲酰化（英语：Formylation reaction）又称甲酰基化或甲酰化作用，是指将一个甲酰官能基加入到一个有机化合物中的化学反应。反之将甲酰基移除的反应称为脱甲酰作用或去甲酰化反应。蛋白质的甲酰化是一种翻译后修饰作用。
Formylation refers to any chemical processes in which a compound is functionalized with a formyl group (-CH=O). In organic chemistry, the term is most commonly used with regard to aromatic compounds (for example, the conversion of benzene to benzaldehyde in the Gattermann–Koch reaction). In biochemistry, the reaction is catalysed by enzymes such as formyltransferases. Formylation generally involves the use of formylation agents, reagents that give rise to the CHO group. Among the many formylation reagents, particularly important are formic acid and carbon monoxide. A formylation reaction in organic chemistry refers to organic reactions in which an organic compound is functionalized with a formyl group (-CH=O). The reaction is a route to aldehydes (C-CH=O), formamides (N-CH=O), and formate esters (O-CH=O).
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