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Certified reference materials (CRMs) are 'controls' or standards used to check the quality and metrological traceability of products, to validate analytical measurement methods, or for the calibration of instruments. [1] A certified reference material is a particular form of measurement standard. Reference materials are particularly important ...
It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon and water, and builds largely upon four key families of chemicals: lipids for cell membranes, carbohydrates such as sugars, amino acids for protein metabolism, and ...
The δ values and absolute isotope ratios of common reference materials are summarized in Table 1 and described in more detail below. Alternative values for the absolute isotopic ratios of reference materials, differing only modestly from those in Table 1, are presented in Table 2.5 of Sharp (2007) [1] (a text freely available online), as well as Table 1 of the 1993 IAEA report on isotopic ...
An overview of the different components included in the field of chemical biology. Chemical biology is a scientific discipline between the fields of chemistry and biology.The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. [1]
A primary standard in metrology is a standard that is sufficiently accurate such that it is not calibrated by or subordinate to other standards. Primary standards are defined via other quantities like length, mass and time. Primary standards are used to calibrate other standards referred to as working standards. [1] [2] See Hierarchy of Standards.
A biomolecule or biological molecule is loosely defined as a molecule produced by a living organism and essential to one or more typically biological processes. [1] Biomolecules include large macromolecules such as proteins , carbohydrates , lipids , and nucleic acids , as well as small molecules (Micromolecules) such as vitamins and hormones.
The reservoir contains the amount of material M under consideration, as defined by chemical, physical or biological properties. The source Q is the flux of material into the reservoir, and the sink S is the flux of material out of the reservoir. The budget is the check and balance of the sources and sinks affecting material turnover in a reservoir.
The term is used in a similar sense in synthetic and organic chemistry, where the substrate is the chemical of interest that is being modified. In biochemistry, an enzyme substrate is the material upon which an enzyme acts. When referring to Le Chatelier's principle, the substrate is the reagent whose concentration is changed.