DNA genes and

The in vitro assays described below can be run in a cell-free or cell-based manner. It should be obvious that for cell-based assays, the result will be dependent on the type of cell used, the media to which the cell is exposed and the developmental stage of the cell. Although all cells from a given individual share the same DNA, genes and pathways are turned on in a cell type-specific manner. For instance, xenobiotic metabolizing enzymes are expressed at high levels in hepatocytes, but not in most epithelial cells. Cell types are characterized as primary (taken directly from an animal and used immediately) or immortalized cell lines, which are typically derived from... 

TABLE 24-2 DNA, Gene, and Chromosome Content in Some Genomes... 

An animated primer on basic aspects of DNA, genes, and heredity produced for the Cold Spring Harbor Laboratory. 

Figure 17.2.1. DNA, genes and proteins. Each gene consists of a coding sequence and a promoter sequence. The coding sequence contains the information or blueprint for new proteins and the promoter contains a regulatory sequence or switch . This switch can be turned on or off by regulatory proteins, controlling gene expression.

Watson, James D., et al. Recombinant DNA Genes and Genomes—A Short Course. 3d ed. New York W. H. Freeman, 2007. One of the landmark texts of recombinant DNA technology, this work presents the fundamental concepts of genetics and genomics, the Human Genome Project, bioinformatic and experimental techniques, and a survey of epigenetics and RNA interference. 

Genotoxicity testing evaluates the test article s ability to cause damage to DNA, genes, and chromosomes. Because of this, genotoxicity testing is performed as a battery, which typically consists of a bacterial reverse mutation assay, also known as the Ames assay, a mouse micronucleus test, and a mouse lymphoma or chromosomal aberration test. 

Another application to biomedicine is to use Raman probing to study DNA biotargets and to identify sequence genes. In fact SERS has been applied to such problems [174]. 

Having settled on a definition of chemoinformatics, it is time for us to reflect on the distinction between chemoinformatics and bioinformatics. The objects of interest of bioinformatics are mainly genes and proteins. But genes, DNA and RNA, and proteins are chemical compounds They are objects of high interest in chemistry, Chemists have made substantial contributions to the elucidation of the structure and function of nucleic adds and proteins. The message is dear there is no clearcut distinction between bioinfonnatics and chemoinformatics I... 

Recombinant DNA techniques have provided tools for the rapid determination of DNA sequences and, by inference, the amino acid sequences of proteins from structural genes. The number of such sequences is now increasing almost exponentially, but by themselves these sequences tell little more about the biology of the system than a New York City telephone directory tells about the function and marvels of that city. 

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