fraction A separate portion of a mixture, often used to describe the part that contains a particular molecular species.
fractionation range The range of molecular sizes that can fit (or diffuse) into the pores of a gel filtration chromatography medium particle.
free radicals Short-lived, highly reactive molecular fragments that are often capable of initiating/continuing chemical reactions by means
of a chain reaction mechanism. They are usually formed by the splitting of molecular bonds, which requires energy input. Free
radicals act as initiators or intermediates in oxidation, combustion, polymerization, and photolysis.
Fourier transform infrared
spectroscopy; an analytical method that measures the ability of a sample to absorb different wavelengths of infrared radiation: How much
is absorbed at each wavelength indicates the types of chemical bonds present in the molecules of the sample. The Fourier-transformation
is a mathematical method used to interpret the vibrations of functional molecular groups and highly polar bonds. FT-IR produces
a "fingerprint" illustrating the vibrational features of all sample components.
functional genomics A method of selecting among the thousands of drug leads that can come out of discovery efforts. Whereas genomics studies
the genetic basis of organisms and their diseases, functional genomics challenges drug lead candidates derived from genomic
studies with early development-style assays to build as much information as possible about the potential drug into the discovery
fusion partner When making a small protein or peptide in E. coli, it is often necessary to produce the protein fused to a larger protein to get high levels of stable expression. The resulting
fusion protein must be cleaved (chemically or enzymatically) to yield the desired protein or peptide. The nonproduct fusion
partner is left over and usually thrown away.
fusion protein A protein containing amino acid sequences from each of two distinct proteins. It is formed by expression of a recombinant
gene in which two coding sequences have been joined together. Typically this is accomplished by cloning a cDNA into an expression
vector in frame with an existing gene.
gas chromatography Analytical method in which a volatile substance to be separated is introduced into a stream of nonreactive gas or other
stationary phase. For example, in capillary gas chromatography, the gas mixture moves through a tube coated with liquid, and
how fast it moves
through the tube depends on the degree to which it stays in the nonreactive gas or dissolves in the liquid (partitioning).
Good clinical practice; according to 21 CFR Parts 56, 312, and 314, the regulations that govern the actions and environment of those working in clinical
testing of drugs and medical devices on human beings. These regulations include rules for obtaining informed consent and data
gene The unit of inheritance consisting of a sequence of DNA occupying a specific position within the genome. Three types of genes
have been identified: structural genes encoding particular proteins; regulatory genes controlling the expression of the other
genes; and genes for transfer RNA or ribosomal RNA instead of proteins.
gene therapy Treats, cures, or prevents disease by changing the expression of a person's genes or inserting genes into the genome. In
its infancy, current gene therapy is primarily experimental, with most human clinical trials only in the research stages.
Gene therapy can target somatic (body) or germ (egg and sperm) cells. In somatic gene therapy, the recipient's genome is changed,
but the change is not passed along to the next generation. In germ-line gene therapy, the parents' egg and sperm cells are
changed with the goal of passing on the changes to their offspring.
genetic engineering Altering the genetic structure of an organism (adding foreign genes, removing native genes, or both) through technological
means rather than traditional breeding.
Genomics studies whole-organism genomes, such as that represented here (all the chromosomes in a single human's cells).
genomics Study of the genetic make-up of organisms, including sequencing and mapping of their DNA. The Human Genome Project was a government-coordinated
effort of many genomics researchers who sequenced and mapped the entire human genome.
genotoxicity Ability of a substance to damage the genome.
genotoxin A substance that causes damage to an organism's DNA.
genotype The genetic composition of an organism (including expressed and nonexpressed genes), which may not be readily apparent. Compare
to phenotype, the outward characteristics that result from gene expression.
germ cell The "sex cells" in higher animals and plants that carry only half of the organism's genetic material and can combine to develop
glass state The amorphous solid that, for example, contains the therapeutic protein in lyophilization; any material that takes the shape
of its container and is formed by cooling a liquid until it is rigid but not crystallized.
Glutamine; one of over 20 naturally occurring amino acids.