Category: O

Enzymatic cleavage of one of the phosphate ester bonds of ATP to yield ADP and a single phosphate molecule known as orthophosphate (designated as ?,). The cleavage of the phosphate bond is energy-yielding and is (except in the case of a futile cycle) coupled enzymatically to reactions that utilize the energy to run the cell.…

The production of entire organs, usually from basic cells, such as fibroblasts, and structural material such as collagen. The processes by which organs form and develop. Much of these processes occur during embryonic development and continue during the fetal period and after birth. The development of specific organs in the course of embryonic and fetal…

An international organization comprised of the world’s wealthiest (most developed) nations. In 1991, the OECD’s Group of National Experts on Safety in Biotechnology (GNE) completed a document entitled Report on the Concepts and Principles Underpinning Safety Evaluations of Food Derived from Modem Biotechnology. The “aim of that document was to elaborate the scientific principles to…

A fiberoptic sensor made by coating the tip of a (glass) optic fiber with an antibody that fluoresces when the antibody comes in contact with its corresponding antigen. Alternatively, the fiber tip is sometimes coated with a dye that fluoresces when the dye comes in contact with specific chemicals (e.g., oxygen, glucose, etc.). Functionally, a…

The temperature at which the maximum growth occurs or maximal enzymatic activity occurs or at which any reaction occurs maximally. The temperature at which a procedure is best carried out, such as the culture of a given organism or the action of an enzyme. The optimal temperature for a specific process, like growing microbes or…

The pH (level of acidity) at which maximum growth occurs or maximal enzymatic activity occurs or at which any reaction occurs maximally.  

The absorbance of light of a specific wavelength by molecules normally dissolved in a solution. Light absorption depends upon the concentration of the absorbing compound (chemical entity) in the solution, the thickness of the sample being illuminated, and the chemical nature of the absorbing compound. An analytical instrument known as a spectrophotometer is used to…

The capacity of a substance to rotate the plane of polarization of plane-polarized light when examined in an instrument known as a polarimeter. All compounds that are capable of existing in two forms that are nonsuperimposable mirror images of each other exhibit optical activity. Such compounds are called stereoisomers (or enantiomers or chiral molecules) and…

A gene unit consisting of one or more genes that specify a polypeptide and an operator unit that regulates the structural gene, that is, the production of messenger RNA (mRNA) and hence, ultimately, of a number of proteins. Generally an operon is defined as a group of functionally related structural genes mapping (that is, being)…

Also known as the “o locus.” The site on the DNA to which a repressor molecule binds to prevent the initiation of transcription. The operator locus is a distinct entity and exists independently of the structural genes and the regulatory gene. It is the structural/biochemical “switch” with which the operon is turned on or off,…