G

Galactose
A sugar contained in milk. Galactose makes up half of the sugar called lactose that is found in milk. Lactose is called a disaccharide, di meaning 2, since lactose is made up of two sugars, galactose and glucose, bound together. Galactose is metabolized through the action of an enzyme called GALT (galactose-1-phosphate uridyl transferase).

Galactosemia
A genetic metabolic disease in which there is a defect in the body's ability to use the sugar galactose. In classic galactosemia, the basic defect is a deficiency of the enzyme known as GALT (galactose-1-phosphate uridyl transferase). This causes an accumulation of galactose 1-phosphate which damages the liver, eye, brain and kidney. Galactosemia is one of the diseases in many newborn screening panels. The disease can be fatal, if undetected. If detected, it can be treated by avoiding galactose in the diet. Galactosemia is inherited as an autosomal recessive trait. People with galactosemia are unable to metabolize the simple sugar galactose. Galactose makes up half of the sugar called lactose that is found in milk. If an infant with galactosemia is given milk, galactose builds up in the infants system causing damage to the liver, brain, kidneys and eyes. Individuals with galactosemis cannot tolerate any form of milk (human or otherwise) or any other galactose-containing food. Exposure to milk products will result in liver damage, mental retardation, cataract formation, and kidney failure.

Gallbladder
A pear-shaped organ just below the liver that stores the bile secreted by the liver. During a fatty meal, the gallbladder contracts, delivering the bile through the bile ducts into the intestines to help with digestion.

Gastritis
Inflammation of the stomach.

Gastroenteritis
Inflammation of the stomach and the intestines. Can cause nausea and vomiting and/or diarrhea. Gastroenteritis has numerous causes : including infectious organisms (viruses, bacteria, etc.), food poisoning, and stress.

Gastroenterologist
A physician who specializes in the diagnosis and treatment of disorders of the gastrointestinal tract, including the esophagus, stomach, small intestine, large intestine, pancreas, liver, gallbladder, and biliary system.

Gastroscope
A flexible, lighted instrument that is put through the mouth and down the esophagus to view the stomach. Tissue from the stomach can also be removed through the gastroscope.

Gene
The basic biological unit of heredity. A segment of deoxyribonucleic acid (DNA) needed to contribute to a function.

Genome
All of the genetic information, the entire genetic complement, all of the hereditary material possessed by an organism.

Glucose
The simple sugar (monosaccharide) that serves as the chief source of energy in the body. Glucose is the principal sugar the body makes. The body makes glucose from proteins, fats and, in largest part, carbohydrates. Glucose is carried to each cell through the bloodstream. Cells, however, cannot use glucose without the help of insulin. Glucose is also known as dextrose.

Gluten
A protein found in wheat or related grains and many foods that we eat. Gluten can be found in a large variety of foods including soups, salad dressings, processed foods and natural flavorings. Unidentified starch, binders and fillers in medications or vitamins can be unsuspected sources of gluten.