Glossary D-G

Detoxification: The neutralization of or degradation of toxic or otherwise dangerous substances. The liver is responsible for the detoxification of many of the dangerous substances created or ingested by the human body.

DNA: The abbreviation for deoxyribonucleic acid, the genetic material of nearly all forms of life. DNA is used to store the genetic information of all living creatures, with the exception of the RNA viruses.

Double helix: The structure of DNA described and discovered by Watson and Crick.

Edema: Swelling on any part of the body due to a collection of fluid into the intercellular spaces of tissues.

Electron microscope: Invented in the 1930's, an electron microscope uses focused beams of electrons to create extremely magnified images. Traditional light microscopes (visible light passed through a series of magnifying lenses) can only magnify images 1,000 to 2,000 times - the electron microscope made it possible magnify images 300,000 times or more. To create the images, a filament inside an electron "gun" shoots a stream of electrons through a stack of electromagnetic lenses, which focus the electrons into a beam. The beam is directed to a fine point on the specimen, and scans across it rapidly. The sample responds by emitting electrons that are picked up by a detector inside the sample chamber, beginning an electronic process that results in an image that can be displayed on a TV screen.

Endoplasmic reticulum: An extensive network of fine parallel membranes interspersed throughout the cytoplasm of the cell, used for the transport of substances inside of

a cell.

End-stage liver disease: The stage when liver disease has progressed to the point where the liver can no longer carry out its functions properly.

Enzyme: A protein secreted by the body which acts as a catalyst by promoting or accelerating a chemical change in other substances while remaining unchanged in the process.

Epidemiology: The scientific study of epidemics and epidemic diseases, especially the factors that influence the incidence, distribution, and control of infectious diseases; the study of disease occurrence in human populations.

Episome: A class of genetic elements of bacteria that may exist either as autonomous entities, replicating in the host independent of the bacterial chromosome, or as segments of the bacterial chromosome, replicating with it.

Fat: Any of several organic compounds that yield fatty acids and glycerol upon saponification.

Fatty acid: Any of a large group of organic acids made up of molecules containing a carboxyl group at the end of a long hydrocarbon chain; the carbon content may very from C2 to C34.

Gastrointestinal tract: The stomach and the intestines.

Gene: A hereditary unit or sequence of genetic material occupying a fixed position in the chromosome, and capable of reproducing itself at each cell division and of managing the formation of protein.

Genetic engineering: The intentional production of new genes and alteration of genomes by the substitution or addition of new genetic material.

Genetic material: Consisting of either RNA (a few viruses) or DNA (all other organisms), genetic material stores the fundamental information necessary to life - information that controls reproduction, development, behavior, and so forth.

Genome: A complete set of chromosomes.

Genotype: The genetic or hereditary constitution of an individual.

Glucagon: The protein hormone secreted by alpha-cells of the pancreas which plays a role in carbohydrate metabolism.

Glucose- 6-Phosphate: A microsomal enzyme catalyzing the hydrolysis of glucose- 6- phosphate to glucose and inorganic phosphate; present in the liver, kidney, intestinal mucosa, and endomentrium.

Glycogen: The form in which carbohydrate is stored in the body, especially in the liver and muscles; it is broken down as needed to glucose molecules.

Golgi apparatus: A complex cellular organelle consisting mainly of a number of flattened sacs and associated vesicles which is involved with the synthesis of glycoproteins, lypoproteins, membrane-bound proteins, and lysosoaml enzymes. The enzymes modify created proteins and other chemicals for use outside the cell. Once modified, they are transported by vesicles to the cell surface, the plasma membrane, where they are secreted into the outside environment.

Guanine: A crystalline purine base, one of the four basic nucleotides that comprise DNA.

HCV: An abbreviation for the hepatitis C virus.