Chemistry classification systems

Mechanistic classification system, 13 441 Mechanistic kinetic expressions, 10 85-88 Mechanistic organic chemistry, high... 

Lennernaes, H. and Abrahamsson, B. (2006) The biopharmaceutics classification system. Comprehensive Medicinal Chemistry II, 5, 971-988. 

In this section, enzymes in the EC 2.4. class are presented that catalyze valuable and interesting reactions in the field of polymer chemistry. The Enzyme Commission (EC) classification scheme organizes enzymes according to their biochemical function in living systems. Enzymes can, however, also catalyze the reverse reaction, which is very often used in biocatalytic synthesis. Therefore, newer classification systems were developed based on the three-dimensional structure and function of the enzyme, the property of the enzyme, the biotransformation the enzyme catalyzes etc. [88-93]. The Carbohydrate-Active enZYmes Database (CAZy), which is currently the best database/classification system for carbohydrate-active enzymes uses an amino-acid-sequence-based classification and would classify some of the enzymes presented in the following as hydrolases rather than transferases (e.g. branching enzyme, sucrases, and amylomaltase) [91]. Nevertheless, we present these enzymes here because they are transferases according to the EC classification. 

The dimension of a space equals the number of elements in a basis, which is defined as a set of elements such that every element in the space is equal to a unique linear combination of them. Therefore, P steady-state mechanisms can be chosen in terms of which all others can be uniquely expressed. This gives us a unique way to symbolize each steady-state mechanism and its overall reaction, but it does not provide a classification system for them which is valid from a chemical viewpoint, because the choice of a basis is arbitrary and is not dictated, in general, by any consideration of chemistry. A classification system for mechanisms is our next topic. 

Irons largely or entirely consist of nickel-iron alloys. At least some of them are probably the remains of core materials of the planetesimals that once existed in the solar system (Dalrymple, 1991, 274). Based on their chemistry, irons are subdivided into several types, which are usually identified with Roman numerals and letters (IAB, IC, IVA, etc.) Krot, Keil and Goodrich (2004) discusses a common classification system for irons. 

All enzymes are named according to a classification system designed by the Enzyme Commission (EC) of the International Union of Pure and Applied Chemistry (IUPAC) and based on the type of reaction they catalyze. Each enzyme type has a specific, four-integer EC number and a complex, but unambiguous, name that obviates confusion about enzymes catalyzing similar but not identical reactions. In practice, many enzymes are known by a common name, which is usually derived from the name of its principal, specific reactant, with the suffix -ase added. Some common names do not even have -ase appended, but these tend to be enzymes studied and named before systematic classification of enzymes was undertaken. 

Dmitri Ivanovitch Mendeleev (1834-1907) was bom in Siberia and studied chemistry at St. Petersburg Institute in Russia. He went on to become a science teacher and later a lecturer and researcher at the University of St. Petersburg. It was through his experience as a teacher that Mendeleev realized a classification system of the known elements was needed. Earlier attempts were made to order the known elements, but they suffered from either being too simplistic or led to inconsistencies that limited their usefulness. 

The chemical abstracting journals have been discussed. These other aids for searching for dissertations cover all dissertations, and it is necessary to consult their classification systems and indexes to find chemistry dissertations. 

It is important to realize that these classification schemes are manmade, which means that we make up the categories and classes. The classification schemes can change, if someone comes up with a system that scientists like better than the present system. The present classification scheme for chemistry will probably seem very simple and elegant to you, especially if you have recently studied the classification system of biology. 

Medicinal Chemistry Definitions and Objectives, Drug Activity Phases, Drug Classification Systems... 

Bums, J. A. and Whitesides, G. M., Feed-forward neural networks in chemistry mathematical systems for classification and pattern recognition, Chem. Rev., 93, 2583,... 

The systematic name of an enzyme consists of two parts, the first originating from the equation, the second from the type of reaction catalyzed. In addition, according to the recommendations of the International Union of Pure and Applied Chemistry and the International Union of Biochemistry (1973), each enzyme bears a number from the international EC (Enzyme Classification) system, which reflects the main class, the subclass, and the subgroup. The number is completed by a special enzyme number. Thus, for example the EC number 1.1.3.4 of the enzyme with the trivial name glucose oxidase results from the following ... 

In this paper the need for an intelligent support of computational chemistry software packages was stressed and the memory-based classification systems suitable for this task recommended. More experiments with selection of relevant features to determine similarity of molecules and methods from the point of view of calculation of molecular properties are needed. Classification systems, such as the FSM, are ready to handle the data, but the task of collecting large amount of data to create a useful system is quite demanding. 

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