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Why is fructose oxidized by fehling's reagent even though it is a ketose?
Wiki User
∙ 14y ago
Fehling's reagent contains CuO and NaOH. I think fructose could give a positive test because the OH- can react with the sugar and "move" the carbonyl around the carbon backbone, including to the terminal position, forming an aldehyde. If the aldehyde reacts with the CuO pretty quickly, then you may have created an "aldehyde sink" that could consume all of your fructose into the carboxylic acid.
Wiki User
∙ 14y ago
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Can Seliwanoff's test be used to distinguish sucrose from fructose?
Yes, fructose is a ketose, for which Seliwanoff's test is most sensitive. Sucrose is neither entirely a ketose nor an aldose, but is a mixture of both. It will react, but more slowly, producing a much lighter pinkish color.
What are examples of ketoses?
The simplest of all ketones, PROPANONE: CH3 - C=OlCH3
What monosaccharide is found in fruit?
fructoseThe monosaccharide responsible for sweet taste in fruit is fructose also known as levulose or fruit sugar.
Why o-toluidine method cannot be used for the detection of fructose in a solution?
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Is xylose a reducing sugar?
Ribose: Ribose is an Aldopentose sugar, and all aldose sugars are reducing sugars. The non-reducing sugars are ketose sugars which contain a ketone functional group. For ex: Ketose = Sucrose. For ex: Aldose = Glucose, Fructose, Lactose
What happen when you react sugar like glucose and fructose with tollen' s reagent and the Fehlings solution?
Glucose oxidizes very quickly, and creates a silver mirror layer between the glucose solution and the Tollens' reagent. This is because of how the ketose reacts and reduces the silver molecules in Tollen's reagent.
Can Seliwanoff's test be used to distinguish sucrose from fructose?
Yes, fructose is a ketose, for which Seliwanoff's test is most sensitive. Sucrose is neither entirely a ketose nor an aldose, but is a mixture of both. It will react, but more slowly, producing a much lighter pinkish color.
How do you distinguish glucose and fructose?
Glucose is an aldose whereas fructose in a ketose. There is a simple qualitative test for distinguishing between D-Glucose and D-Fructose.
What is the result of the seliwanoff test if the solution contains both fructsoe and glucose?
the glucose would remain yellow which is the initial colour of the seliwanoff's reagent. the fructose however being a ketose forms a furfural because of the HCL present in the seliwanoff reagent and reacts with the resorcinol to give a red cherry or pink colour.
What are examples of ketoses?
The simplest of all ketones, PROPANONE: CH3 - C=OlCH3
Can you name one or two monosaccharides made by plants?
Glucose and fructose are monosaccharides made by plants. Glucose is a simple aldose, fructose is a ketose.
Why the majority said that sucrose is a ketose sugar?
The majority would be incorrect. Sucrose is not considered an aldose or a ketose, because it is a disaccharide made from glucose (an aldose) and fructose (a ketose). So, it has both properties within its structure. It is a non-reducing sugar.It is possible that many say sucrose is a ketose because sucrose will fail the Benedict's test, which is designed to detect aldoses.
What monosaccharide is found in fruit?
fructoseThe monosaccharide responsible for sweet taste in fruit is fructose also known as levulose or fruit sugar.
What test can be used to identify the presence of the fructose?
Seliwanoff's test is used to differentiate aldose [glucose] from ketose [fructose]. Seliwanoff's reagent is composed of resorcinol and HCl. When heated with concentrated hydrochloric acid, the polysaccharides and oligosaccharides hydrolyze to yield monosaccharides. Then, resorcinol reacts in the dehydrated ketose to form oxymethylfurfurol produce a deep cherry red color [red precipitate]. Aldoses produces a faint pink colored solution.
Why do fructose and galactose have different names when they have the same atoms and the numbers are the same?
The difference is actually in their structures. Galactose is an aldose wiith formyl functional group and belongs ti aldehydes. Whereas fructose is ketose and belongs to ketones.
Why o-toluidine method cannot be used for the detection of fructose in a solution?
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What is the difference between ketose and aldose?
An aldose is also called the aldosugar and has a functional group of an aldehyde group. Examples are glucose and glyceraldehyde. While a ketose is also called the ketosugar and has a functional group of of a keto group. Examples are fructose and dihydroxyacetone.
