Chemically defined formula

The oligomeric formulas are also known as chemically defined formulas. This class of formulas can be subcategorized based on whether the formula contains all free amino acids (elemental formulas) or peptides (peptide-based) as the protein source. Some of these formulas contain a combination of free amino acids and small peptides. Actually, dipeptides and tripeptides in these formulas are absorbed more efficiently than free amino acids. Oligomeric formulas may be better tolerated than polymeric formulas for patients with defects in GI function and maybe particularly useful in patients with severe pancreatic dysfunction or significantly decreased GI surface area (e.g., short bowel syndrome). 

Normality is the number of equivalent weights (EW) per unit volume and, like formality, is independent of speciation. An equivalent weight is defined as the ratio of a chemical species formula weight (FW) to the number of its equivalents... 

Formality, F The number of formula masses of solute contained in each liter of solution synonymous with analytical molarity. Formal potential, The electrode potential for a couple when the analytical concentrations of all participants are unity and the concentrations of other species in the solution are defined. Formula weight The summation of atomic masses in the chemical formula of a substance synonymous with gram formula weight and molar ma.ss. 

Most general EN formulas contain an equal balance of nonprotein energy between carbohydrate and fat. Elemental or chemically defined products are the exception because they are intended to be high-carbohydrate, low-fat formulas to enhance absorption and digestion. In pulmonary patients administration of a high-carbohydrate formula... 

With low molecular weight chemical compounds having a clearly defined formula, there is no problem with molecular weight determination and its description. For ethylene (CH2=CH2), for example, molecular weight is 28. 

The data of paramagnetic diatomic molecules (defined as those wifli a paramagnetic ground state) will appear later in subvolume 11/29E1. The reader will find, however, the chemical sum formulae of investigated paramagnetic diatomic species listed already in subvolume A1 in alphabetic order, together with some references to pertinent literature. 

Once the standard chemical potential fif has been defined, formulae follow for all the other standard thermodynamic functions obtained by differentiation of ju, with respect to temperature. In particular,... 

Feeding of infants with formulas represents a considerable MRPs load. N -(carboxymethyl)lysine (CML) represents a chemically-defined MRP, and widely used indicator of the Maillard reaction in foods. Theoretical daily burden of dietary CML in 6-month-old breast-fed infants represents 0.01-0.03 mg/d, while in the formula-fed children 4.614.2 mg/d". In comparison with the breast-fed children, high dietary intake of CML in formula-fed infants results in significantly higher plasma CML concentration (+46%), and... 

Historically carbohydrates were once considered to be hydrates of carbon because their molecular formulas m many (but not all) cases correspond to C (H20) j It IS more realistic to define a carbohydrate as a polyhydroxy aldehyde or polyhydroxy ketone a point of view closer to structural reality and more suggestive of chemical reactivity... 

Consider, for example, the protein shown in Figure 15.7. The bottom left-hand amino acid is valine, which is linked to proline. Suppose for the sake of argument that we wanted to treat this valine quantum-mechanically and the rest of the protein chain according to the methods of molecular mechanics. We would have to draw a QM/MM boundary somewhere between valine and the rest of the protein. The link atoms define the boundary between the QM and the MM regions. A great deal of care has to go into this choice of boundary. The boundary should not give two species whose chemical properties are quite different from those implied by the structural formulae on either side of this boundary. 

Structural Formula Complex protein structure not precisely defined Chemical Abstracts Registry No. 9008-11 -1... 

Cell growth and metabolic activities are similarly described as a simple chemical reaction. It is also necessary to establish a definite formula for dry cell matter. The elemental composition of certain strains of microorganism is defined by an empirical formula CHaO/3Ns. The general biochemical reaction for biomass production is based on consumption of organic substrate, as shown below. Substrate oxidation is simplified in the following biochemical oxidation ... 

A model is one of the main outcomes of ary scientific enquiry and hence is a major contributor to philosophy of science. A model may be defined as a simplified representation of a phenomenon (an object, system, event, process) or idea produced for the specific purpose of providing an explanation of that entity, the most important outcomes of which are the production of successful predictions of how it will behave under a range of circumstances (Gilbert, Boulter, Elmer, 2000). Entities can be modelled at the three levels at the macroscopic, by representing some of the aspects of the entity that can be seen at the sub-microscopic, by representing the ideas produced to explain the constitution and behaviour of the particles that constitute the entity and at the symbolic, by representing the symbols created to simplify the reference to such particles (as, for instance, chemical formulae and chemical equations). 

Complex ions, also called coordination complexes, have well-defined stoichiometries and structural arrangements. Usually, the formula of a coordination complex is enclosed in brackets to show that the metal and all its ligands form a single structural entity. When an ionic coordination complex is isolated from aqueous solution, the product is composed of the complex ion and enough counter-ions to give a neutral salt. In the chemical formula, the counter-ions are shown outside the brackets. Examples include the sulfate salt of [Ni (NH3)g, ... 

The real energy of ion solvation, af, defined by Eq. (2), expresses the change in ion energy upon its transfer from a gas phase into a solution. Unlike the chemical energy of solvation, psi, the value of the real energy of solvation, also in the standard state, can be calculated from experimental data using the formula, e.g., for the hydration of the cation ... 

A mathematical device, the NSS, which can be related to Artificial Intelligence techniques, has been defined and applied in order to solve or reformulate some quantum chemical problems. This symbol is related to computer formulae generation. It has been shown that by means of the use of NSS s many applications of such symbols can be found in mathematics as well as in Mathematical Chemistry in particular. 

The very basis of the kinetic model is the reaction network, i.e. the stoichiometry of the system. Identification of the reaction network for complex systems may require extensive laboratory investigation. Although complex stoichiometric models, describing elementary steps in detail, are the most appropriate for kinetic modelling, the development of such models is time-consuming and may prove uneconomical. Moreover, in fine chemicals manufacture, very often some components cannot be analysed or not with sufficient accuracy. In most cases, only data for key reactants, major products and some by-products are available. Some components of the reaction mixture must be lumped into pseudocomponents, sometimes with an ill-defined chemical formula. Obviously, methods are needed that allow the development of simple... 

The designation (aq) indicates a water solution. (Three other chemical states and their formula notations include liquid [1], solid [s], and gas [g].) The substance is in a solution, which is defined as a homogenous mixture of two or more substances. Homogenous means that the solution has a uniform chemical makeup. In other words, if you took samples of a solution from two different areas of its container, the two samples would look the same and have the same chemical composition, as would, say, two spoon-0 fills of vanilla ice cream scooped from different parts of the same... 

The equivalent is defined in terms of a chemical reaction. It is defined in one of two different ways, depending on whether an oxidation-reduction reaction or an acid-base reaction is under discussion. For an oxidation-reduction reaction, an equivalent is the quantity of a substance that will react with or yield 1 mol of electrons. For an acid-base reaction, an equivalent is the quantity of a substance that will react with or yield 1 mol of hydrogen ions or hydroxide ions. Note that the equivalent is defined in terms of a reaction, not merely in terms of a formula. Thus, the same mass of the same compound undergoing different reactions can correspond to different numbers of equivalents. The ability to determine the number of equivalents per mole is the key to calculations in this chapter. 

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