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Benedict's reagent (often called Benedict's qualitative solution or Benedict's solution) is a chemical reagent and complex mixture of sodium carbonate, sodium citrate, and copper(II) sulfate pentahydrate. [1] It is often used in place of Fehling's solution to detect the presence of reducing sugars and other reducing substances. [2]
Since its discovery in 1904 until the 1960s, the Wöhlk test has mainly been used to detect the reducing disaccharide lactose in urine in medical laboratories. Although there were already a number of wet-chemical detection methods to identify sugars, such as the Fehling or Benedict test , those analyses could only differentiate between reducing ...
Bifidobacterium in the human intestine have been found to contain type I chain lacto-N-biosidases capable of cleaving lacto-N-tetraose to lactose-N-biose and lactose. [ 11 ] Lacto- N -tetraose is a non-competitive food source for B. infantis with other enteric bacteria lacking the required proteins and incapable of degrading the sugar into ...
Reducing disaccharides like lactose and maltose have only one of their two anomeric carbons involved in the glycosidic bond, while the other is free and can convert to an open-chain form with an aldehyde group. The aldehyde functional group allows the sugar to act as a reducing agent, for example, in the Tollens' test or Benedict's test.
All monosaccharide ketoses are reducing sugars, because they can tautomerize into aldoses via an enediol intermediate, and the resulting aldehyde group can be oxidised, for example in the Tollens' test or Benedict's test. [3] Ketoses that are bound into glycosides, for example in the case of the fructose moiety of sucrose, are nonreducing ...
Lactic acidosis refers to the process leading to the production of lactate by anaerobic metabolism. It increases hydrogen ion concentration tending to the state of acidemia or low pH. The result can be detected with high levels of lactate and low levels of bicarbonate. This is usually considered the result of illness but also results from ...
The patient is then given a small amount of pure lactose (typically 20 to 25 g), and then required to take readings every 15, 30 or 60 minutes for two to three hours. If the level of hydrogen rises above 20 ppm (parts per million) over the lowest preceding value within the test period, the patient is typically diagnosed as a lactose malabsorber ...
Fehling's test can be used as a generic test for monosaccharides and other reducing sugars (e.g., maltose). It will give a positive result for aldose monosaccharides (due to the oxidisable aldehyde group) but also for ketose monosaccharides, as they are converted to aldoses by the base in the reagent , and then give a positive result.