Fructose is a simple sugar (monosaccharide) found in many foods and one of the three most important blood sugars along with glucose and galactose. Honey, tree fruits, berries, melons, and some root vegetables such as: beets, sweet potatoes, parsnips and onions, contain fructose; usually in combination with sucrose and glucose. Fructose is also derived from the digestion of sucrose, a disaccharide consisting of glucose and fructose which is broken down by enzymes during digestion. Fructose is often recommended for, and consumed by, people with diabetes mellitus or hypoglycemia, because it has a very low Glycemic Index (Glycemic Index 32) relative to cane sugar (sucrose). The low GI is due to the unique and lengthy metabolic pathway of fructose, which involves phosphorylation and a multi-step enzymatic process in the liver. See #health effects and glycation for further informations. ==Structure==
Fructose, or levulose, is a levorotation monosaccharide with the same empirical formula as glucose but with a different structure. Although fructose is a hexose (6 carbon atoms), it generally exists as a 5-membered hemiketal ring (a furanose).
The first -OH points the opposite way from the second and third -OH.
===Isomerism===
D-Fructose has the same configuration at its penultimate carbon as D-glyceraldehyde. Fructose is more sweet than glucose due to its stereomerism structure
==Health effects== Fructose depends on glucose to carry it into the blood stream via GLUT-5 and then GLUT-2 (Buchs ''et al'' 1998). Absorption of fructose without glucose present is very poor, and excess fructose is carried into the lower intestine where it provides nutrients for the existing flora, which produce gas. It may also cause water retention in the intestine. These effects may lead to bloating, excessive flatulence, loose stools, and even diarrhea depending on the amounts eaten and other factors. Fructose is implicated in producing obesity (Elliott ''et al'' 2002), elevated low density lipoprotein and triglycerides, leading to metabolic syndrome. Fructose also chelates minerals in the blood. This effect is especially important with micronutrients such as copper, chromium and zinc. Since these solutes are normally present in small quantities, chelation of small numbers of ions may lead to deficiency diseases, immune system impairment and even insulin resistance, a component of type II diabetes (Higdon). Fructose is a reducing sugar, as are all monosaccharides. However, it is considered approximately ''ten times'' more active (McPherson ''et al'' 1988) in the formation of glycations than glucose so consumption should be limited in order to limit the consequent glycation-related damage to cellular and molecular function. This may be an important contribution to senescence and many age-related chronic diseases (Levi & Werman 1998). ==See also== *Corn syrup *Fructose intolerance *Fructose malabsorption ==References== * Buchs AE, Sasson S, Joost HG, Cerasi E. ''Characterization of GLUT5 domains responsible for fructose transport.'' Endocrinology 1998;139:827-31. [http://endo.endojournals.org/cgi/content/full/139/3/827 Fulltext]. PMID 9492009. * Elliott SS, Keim NL, Stern JS, Teff K, Havel PJ. ''Fructose, weight gain, and the insulin resistance syndrome.'' Am J Clin Nutr 2002;76:911-22. [http://www.ajcn.org/cgi/content/full/76/5/911 Fulltext]. PMID 12399260. * Levi B, Werman MJ. ''Long-term fructose consumption accelerates glycation and several age-related variables in male rats.'' J Nutr 1998;128:1442-9. [http://www.nutrition.org/cgi/content/full/128/9/1442 Fulltext]. PMID 9732303. * McPherson JD, Shilton BH, Walton DJ. ''Role of fructose in glycation and cross-linking of proteins.'' Biochemistry 1988;27:1901-7. PMID 3132203. * Higdon, J., Linus Pauling Institute, Oregon State U. [http://lpi.oregonstate.edu/infocenter/minerals/chromium/index.html ''Chromium'' 2003] ==External link== *[http://www.medbio.info MedBio] Monosaccharides Nutrition Sweeteners
What do you mean that some people react badly to fructose?? == Structures of L Forms == I have removed these structures from the article because they seem incorrect to me. They are not mirror images of the α-D and β-D forms. The two "front-most" hydroxyls need to be "flipped". I think that the strucures shown are not fructose at all, but some other ketohexose. Oops, forgot to sign. User:Josh Cherry 00:23, 2 Jul 2004 (UTC) I'm sorry about that, and taking a long time to fix it. I've updated the images, can they be included now? User:Sverdrup 08:16, 8 Sep 2004 (UTC) They look right to me now. User:Josh Cherry 01:18, 9 Sep 2004 (UTC) These graphics are still incorrect. In each graphic, where ever CH3 or H3C is found, it should be CH2 or H2C respectively. Thank you for placing these graphics online.... but they need to be accurate before they are borrowed and end up on websites and student papers all over the world. User: Don DeWitt 1 Nov 2004 The same problem exists for the D-isomers. I have created revised images in Photoshop but I do not know how to upload them. The original author may wish to make these corrections and obviously knows how to do it. User: Don DeWitt 1 Nov 2004 One last thought. It would be very helpful if the carbons were numbered in all the graphics. User: Don DeWitt 1 Nov 2004 YAY FOR FRUCTOSE!!! THE BEST MONOSACCHRIDE EVER!!!!! YOU KNO IT!! ;)
See other meanings of words starting from letter:
Words begining with Fructose:
Fructose
Fructose
Fructose-1,6-bisphosphatase
Fructose-1,6-bisphosphatase_deficiency
Fructose_1,6-bisphosphatase
Fructose_bisphosphatase
Fructose_bisphosphatase_deficiency
Fructose_interolace
Fructose_interolace
Fructose_intolerance
Fructose_intolerance
Fructose_intoxication
Fructose_malabsorption
Fructose
Fructose is a simple sugar (monosaccharide) found in many foods and one of the three most important blood sugars along with glucose and galactose. Honey, tree fruits, berries, melons, and some root vegetables such as: beets, sweet potatoes, parsnips and onions, contain fructose; usually in combination with sucrose and glucose. Fructose is also derived from the digestion of sucrose, a disaccharide consisting of glucose and fructose which is broken down by enzymes during digestion. Fructose is often recommended for, and consumed by, people with diabetes mellitus or hypoglycemia, because it has a very low Glycemic Index (Glycemic Index 32) relative to cane sugar (sucrose). The low GI is due to the unique and lengthy metabolic pathway of fructose, which involves phosphorylation and a multi-step enzymatic process in the liver. See #health effects and glycation for further informations. ==Structure==
''Structure formula of fructose'' |
==Health effects== Fructose depends on glucose to carry it into the blood stream via GLUT-5 and then GLUT-2 (Buchs ''et al'' 1998). Absorption of fructose without glucose present is very poor, and excess fructose is carried into the lower intestine where it provides nutrients for the existing flora, which produce gas. It may also cause water retention in the intestine. These effects may lead to bloating, excessive flatulence, loose stools, and even diarrhea depending on the amounts eaten and other factors. Fructose is implicated in producing obesity (Elliott ''et al'' 2002), elevated low density lipoprotein and triglycerides, leading to metabolic syndrome. Fructose also chelates minerals in the blood. This effect is especially important with micronutrients such as copper, chromium and zinc. Since these solutes are normally present in small quantities, chelation of small numbers of ions may lead to deficiency diseases, immune system impairment and even insulin resistance, a component of type II diabetes (Higdon). Fructose is a reducing sugar, as are all monosaccharides. However, it is considered approximately ''ten times'' more active (McPherson ''et al'' 1988) in the formation of glycations than glucose so consumption should be limited in order to limit the consequent glycation-related damage to cellular and molecular function. This may be an important contribution to senescence and many age-related chronic diseases (Levi & Werman 1998). ==See also== *Corn syrup *Fructose intolerance *Fructose malabsorption ==References== * Buchs AE, Sasson S, Joost HG, Cerasi E. ''Characterization of GLUT5 domains responsible for fructose transport.'' Endocrinology 1998;139:827-31. [http://endo.endojournals.org/cgi/content/full/139/3/827 Fulltext]. PMID 9492009. * Elliott SS, Keim NL, Stern JS, Teff K, Havel PJ. ''Fructose, weight gain, and the insulin resistance syndrome.'' Am J Clin Nutr 2002;76:911-22. [http://www.ajcn.org/cgi/content/full/76/5/911 Fulltext]. PMID 12399260. * Levi B, Werman MJ. ''Long-term fructose consumption accelerates glycation and several age-related variables in male rats.'' J Nutr 1998;128:1442-9. [http://www.nutrition.org/cgi/content/full/128/9/1442 Fulltext]. PMID 9732303. * McPherson JD, Shilton BH, Walton DJ. ''Role of fructose in glycation and cross-linking of proteins.'' Biochemistry 1988;27:1901-7. PMID 3132203. * Higdon, J., Linus Pauling Institute, Oregon State U. [http://lpi.oregonstate.edu/infocenter/minerals/chromium/index.html ''Chromium'' 2003] ==External link== *[http://www.medbio.info MedBio] Monosaccharides Nutrition Sweeteners
Fructose
What do you mean that some people react badly to fructose?? == Structures of L Forms == I have removed these structures from the article because they seem incorrect to me. They are not mirror images of the α-D and β-D forms. The two "front-most" hydroxyls need to be "flipped". I think that the strucures shown are not fructose at all, but some other ketohexose. Oops, forgot to sign. User:Josh Cherry 00:23, 2 Jul 2004 (UTC) I'm sorry about that, and taking a long time to fix it. I've updated the images, can they be included now? User:Sverdrup 08:16, 8 Sep 2004 (UTC) They look right to me now. User:Josh Cherry 01:18, 9 Sep 2004 (UTC) These graphics are still incorrect. In each graphic, where ever CH3 or H3C is found, it should be CH2 or H2C respectively. Thank you for placing these graphics online.... but they need to be accurate before they are borrowed and end up on websites and student papers all over the world. User: Don DeWitt 1 Nov 2004 The same problem exists for the D-isomers. I have created revised images in Photoshop but I do not know how to upload them. The original author may wish to make these corrections and obviously knows how to do it. User: Don DeWitt 1 Nov 2004 One last thought. It would be very helpful if the carbons were numbered in all the graphics. User: Don DeWitt 1 Nov 2004 YAY FOR FRUCTOSE!!! THE BEST MONOSACCHRIDE EVER!!!!! YOU KNO IT!! ;)
See other meanings of words starting from letter:
F
FA | FB | FC | FD | FE | FG | FH | FI | FJ | FK | FL | FM | FN | FO | FP | FR | FS | FT | FU | FW | FX | FY | FZ |Words begining with Fructose:
Fructose
Fructose
Fructose-1,6-bisphosphatase
Fructose-1,6-bisphosphatase_deficiency
Fructose_1,6-bisphosphatase
Fructose_bisphosphatase
Fructose_bisphosphatase_deficiency
Fructose_interolace
Fructose_interolace
Fructose_intolerance
Fructose_intolerance
Fructose_intoxication
Fructose_malabsorption
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