|
Home >> Dictionary of Bioinformatics, Biochemistry, Biotechnology >> Glycosuria - Gonadotrophic Hormones (Gonadotrophins)
|
|
Glycoside
A compound formed between a sugar another molecule such as a protein, lipid or an organic molecule.
Glycosidic bonds
The bonds between a sugar and another molecule (alcohol, purine, pyrimidine, sugar) via an intervening O or N atom.
Goitrogen
A substance that inhibits thyroid function. Examples include iodide monovalent anions and organic compounds.
|
Glycosuria
Presence of glucose in the urine. Glycosuria occurs in conditions where the blood glucose concentration exceeds the renal threshold. Diabetes mellitus is the most common cause of Glycosuria with hyperglycaemia. The other cause include endocrinal hyperactivity (hyperthyroidism, hyperpituitarism and Cushing’s syndrome), pancreatic disorders infections, anaesthesia and asphyxia. Emotional stress produced by anger, fear and excitement, can also cause Glycosuria due to increases secretion of epinephrine, Experimentally, Glycosuria can be induced by surgical removal of the pancreas, alloxan and by phorizin, an inhibitor of the renal tubular reabsorption of glucose. Glycosuria without hyperglycaemia indicates a defect in the renal tubular reabsorption of glucose and is termed renal Glycosuria. Renal Glycosuria seen in nondiabetic subjects in whom there is no abnormality of carbohydrate metabolism may be due to decreases renal tubular reabsorption of glucose. It occurs in late pregnancy, Wilson’s disease and in Fanconi syndrome.
|
Glycosylated haemoglobin (HbA1c)
A measure of the average plasma glucose concentration during the preceding 6-8 weeks and an average plasma glucose estimation. Normally, HbA1c represents 6 per cent of total haemoglobin, whereas in diabetes mellitus, HbA1c concentration is increased 2-3 fold. However, an increase may also occur in patients with haemolytic anaemia due to decreases red cell life span.
Glycosylation
The enzymatic addition of sugar residues to amino groups of proteins.
GMP
(Good Manufacturing practice) Codes of practice designed to minimize the chance of accidents which could affect a research project or a manufactured product. The key of GLP and GMP are that all observations and data are recorded, and that only established procedures are used and by people who have the necessary training to use them.
|
|
Glycosylphosphatidylinositol anchor (GPI anchor)
A lipid linkage by which some membrane proteins are bound to the membrane. The anchor is formed as the proteins pass through the endoplasmic reticulum.
Glyoxylate cycle
A pathway for the conversion of acetate into succinate and carbohydrates.
Glyoxysome
An organelle that contains the key enzymes of the glyoxylate cycle.
|
|
|
GM
Genetically modified. Refers to organisms that have been modified by recombinant DNA technology such as GM crops.
GM food
Food that has been partially or fully modified by recombinant DNA technology.
GnRH-associated peptide (GAP)
A neuropeptide containing 56 amino acids that inhibits release of Prolactin.
|
Glycosphingolipids
Lipids containing ceramide (sphingosine-fatty acid) with one or more sugar residues.
GM1 gangliosidosis
A lipid storage disease caused by a deficiency of β-galactosidase inherited as an autosomal recessive trait. Three forms-infantile, juvenile and adult have been identified. he clinical symptoms of he infantile form include mental retardation, seizures, coarse facies, early blinding, retinal cherry red spots, corneal clouding and skeletal dysplasia. The juvenile form has a later onset and is characterised by neurological impairment, seizures and milder skeletal and ocular findings. In adults, the symptoms are less severe and include spasticity, ataxia and minimal bony abnormalities.
GM2 gangliosidosis A lipid storage disease caused by a deficiency of hexosaminidase. There are three variants: Tay - Sachs disease, characterised by a deficiency of hexosaminidase A, Sandhoff disease characterised by a deficiency of hexosaminidase. A and B, and the AB Variant of GM2 gangliosidosis due to deficiency of a protein factor required for th activity of the enzyme.
GMO
See genetically modified organism.
GMP
(guanosine monophosphate) see guanosine.
GnRH test
A test to distinguish between primary and secondary hypogonadism,
GnRH (100 μg) is given intravenous injection. Plasma LH and FSH are determined before and at 30 and 60 minutes following GnRH injection. The response of LH and FSH to GnRH may be normal, decreased or absent in pituitary disease, whereas in hypothalamic disease, it is delayed, normal or decreased.
Gobar
See biogas
Goitre
Enlargement of the thyroid gland.
Goldberg-Hogness (GH) box
Another name for TATA box.
Golden path
A term applied to the first and subsequent assemblies of the human genome.
Glodman equation
An equation that expresses the quantitative relationship between th concentrations of charged species in either side of a membrane and the resting transmembrane potential.
Golgi apparatus
A series of double-membrane structures found in the cytoplasm of plant and animal cells named after the discover, the Italian cytologist Camillo Golgi (1843-1926). The Golgi apparatus interacts with the endoplasmic reticulum and helps in the transport of proteins to other organelles, the plasma membrane or outside the cell (extracellular transport). It also plays a role in th formation of cell wall.
Gonadotrophic hormones (gonadotrophins)
A group of polypeptide hormones chiefly follicle-stimulating hormone (FSH) and luteinising hormone (LH) synthesised by the pituitary gland that stimulate accessory cells around the oocyte to release progesterone, a hormone responsible for the maturation of oocytes. The gonadotrophins appear at the onset of sexual maturity in animals.
Gonadotrophin-releasing hormone (GnRH) or luteinising hormone releasing hormone (LHRH)
A decapeptide synthesised in th hypothalamus that binds high affinity receptors in th anterior pituitary and stimulates the synthesis and secretion of LH and FSH. The secretion of GnRH is episodic and pulsatile. It is increased by noradrenergic agonists and decreased by endogenous opioids.
Gonads
Reproductive organs in animals that produce gametes. The gonads include the male testis, which produces spermatozoa, and the female ovary, which produces ova (egg cells). The gonads also produce hormones that regulate secondary sexual characteristics.
Good laboratory practice
See GLP/GMP
Good manufacturing practise
See GLP/GMP
Goodpasture’s syndrome
An autoimmune disease in which vascular disease is caused by autoantibodies to type IV collagen or basement membrane.
Gopher
A document delivery system that allows the retrieval and display of text based files.
Gout
A disorder characterised by hyperuricaemia with aggregates deposits of sodium urate crystals (tophi) which cause deformation and destruction of hard and soft tissues.
|
|
