| yolk stalk | A narrow tube present in the early embryo that connects the midgut of the embryo (through the umbilical opening) to the yolk sac outside the embryo. Later in development, the yolk stalk is usually obliterated but a remnants of it may persist, most commonly as a finger-like protrusion from the small intestine known as meckel's diverticulum. Found in 2-4% of people, meckel's diverticulum may become inflamed much like the appendix and require surgical removal. The yolk stalk is also called the umbilical duct, vitelline duct, or oomphalomesenteric duct. (12 Dec 1998) |
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| glucose-1-fructose-2-oxidoreductase | <enzyme> Catalyses intermolecular oxidation-reduction of glucose and fructose to form gluconolactone and sorbitol; contains tightly bound nadp as h+ carrier; does not require added cofactor Registry number: EC 1.1.1.- (26 Jun 1999) |
| glucose-fructose oxidoreductase | <enzyme> Isolated from zymomonas mobilis; catalyses the formation of sorbitol and glucono-delta-lactone from glucose and fructose; enzyme contains tightly bound nadp+ Registry number: EC 1.1.99.- (26 Jun 1999) |
| glutamine-fructose-6-phosphate transaminase (isomerizing) | <enzyme> An enzyme that catalyses the synthesis of fructose-6-phosphate plus glutamine from glutamate plus glucosamine-6-phosphate. Chemical name: L-Glutamine:D-fructose-6-phosphate aminotransferase (hexose-isomerizing) Registry number: EC 2.6.1.16 (12 Dec 1998) |
| hereditary fructose intolerance | A metabolic error due to deficiency of hepatic fructose 1,6-bisphosphate aldolase B (which also acts on fructose 1-phosphate); the second enzyme in the specific fructose pathway; vomiting and hypoglycaemia follow ingestion of fructose; prolonged fructose ingestion in young children results in failure to thrive and in jaundice, hepatomegaly, albuminuria, aminoaciduria, and sometimes cachexia and death; autosomal recessive inheritance in most families. (05 Mar 2000) |
| D-fructose 5-dehydrogenase | <enzyme> Catalyses the oxidation of fructose with any acceptor to 5-ketofructose and reduced acceptor Registry number: EC 1.1.99.11 (26 Jun 1999) |
| ferric fructose | A potassium-iron-fructose; a haematinic drug. (05 Mar 2000) |
| 6-phosphofructo-2-kinase-fructose-2,6-bisphosphatase | <chemical> Hepatic bifunctional enzyme that both degrades and synthesises fructose-2,6-bisphosphate Synonym: 6pf-2-k-fru-2,6-p(2)ase, hepatic 6-phosphofructo-2-kinase, hepatic fructose-2,6-bisphosphatase, pfk-2 (liver), pbpase-2 (liver) (26 Jun 1999) |
| fructose | <biochemistry> A 6 carbon sugar (hexose) abundant in plants. Fructose has its reducing group (carbonyl) at C2 and thus is a ketose, in contrast to glucose that has its carbonyl at C1 and thus an aldose. Sucrose, common table sugar, is the nonreducing disaccharide formed by an alpha linkage from C1 of glucose to C2 of fructose (latter in furanose form). Fructose is a component of polysaccharides such as inulin, levan. (18 Nov 1997) |
| fructose 1,6-bisphosphate | <biochemistry> This key intermediate in glycolysis and gluconeogenesis (a hexose diphosphate) was discovered by Arthur Harden and William Young in 1905. In the third step of glycolysis, fructose 6-phosphate and ATP are converted to fructose 1,6-bisphosphate and ADP with the aid of phosphofructokinase. In step 4, fructose 1,6 bisphosphate (with the aid of aldolase) is cleaved into duhydroxyacetone phosphate and glyceraldehyde 3-phosphate. Synonym: hexosebisphosphatase, hexosediphosphatase. (08 Mar 2000) |
| fructose-1,6-diphosphatase deficiency | An autosomal recessive fructose metabolism disorder due to absent or deficient fructose-1,6-diphosphatase activity. Gluconeogenesis is impaired, resulting in accumulation of gluconeogenic precursors (e.g., amino acids, lactate, ketones) and manifested as hypoglycaemia, ketosis, and lactic acidosis. Episodes in the newborn infant are often lethal. Later episodes are often brought on by fasting and febrile infections. As patients age through early childhood, tolerance to fasting improves and development becomes normal. (12 Dec 1998) |
| fructose-1,6-diphosphate reductase | <enzyme> From bovine lens; reduces fructose-1,6-diphosphate to sorbitol-1,6-diphosphate in presence of NADH; 3 isoenzymes which copurify with lactate dehydrogenase isoenzymes Registry number: EC 1.1.1.- Synonym: fdp reductase (26 Jun 1999) |
| fructose 1-phosphate | A fructose derivative that accumulates in individuals with hereditary fructose intolerance. (05 Mar 2000) |
| fructose 2,6-bisphosphate | An analog of fructose 1,6-bisphosphate that plays a key role in the regulation of glycolysis and gluconeogenesis; activates phosphofructokinase and inhibits fructose 1,6-bisphosphatase. (05 Mar 2000) |
| fructose-2,6-bisphosphate 2-phosphatase | <enzyme> Copurifies with 6-phosphofructo-2-kinase; probably is a single protein with both activities; do not confuse with EC 3.1.3.54, fructose-2,6-bisphosphate 6-phosphatase Registry number: EC 3.1.3.46 Synonym: fructose-2,6-diphosphatase, fructose 2,6-bisphosphatase, fructose-2,6-bisphosphatase (26 Jun 1999) |