Sciencemadness Discussion Board

Saccharides to Ketone

ScienceHideout - 21-5-2012 at 11:28

Hi Everyone!

In my science project, I need to test for sugar. Well, I was dumb and bought ketone test strips- because the pharmacist said that it tests for sugar. I was wondering if there is a reagent I can use to convert my monosaccharides into a ketone.

Note- I can not test for dimethyl ketone.

Thanks for any help in advance!
-Dean

Hexavalent - 21-5-2012 at 11:42

This should probably be in the beginners section.

It is difficult to ascertain what you are trying to do . . .

Monosaccharides are the simplest carbohydrates in that they cannot be hydrolyzed to smaller carbohydrates. They are basic units of Carbohydrates. They are made up of only one carbohydrate moiety.

The general chemical formula of an unmodified monosaccharide is (C•H2O) n, literally a "carbon hydrate. This is termed as the empirical formula. In this formula the” n” varies form 3-6 and rarely seven. This implies that in nature no. of carbon atoms found in monosaccharide varies from minimum 3 to maximum 7. The smallest monosaccharides, for which n = 3, are dihydroxyacetone and glyceraldehyde. However, not all carbohydrates conform to this precise stoichiometric definition (e.g., uronic acids, deoxy-sugars such as fucose), nor are all chemicals that do conform to this definition automatically classified as carbohydrates.

Monosaccharides are classified according to three different characteristics:

Placement of its carbonyl group,

Number of carbon atoms it contains, and

Its chiral handedness.

If the carbonyl group is an aldehyde and attached to C-1, the monosaccharide is an Aldose; if the carbonyl group is a ketone attached to C-2, the monosaccharide is a Ketose. Therefore monosaccharides are called aldoses and ketoses derivatives of polyhydric alcohols. Glucose is an example of an aldose and fructose is an example of ketose.

Thus, some saccharides do contain ketone groups and therefore could partially be classified in some ways as ketones (the complex carbs are known as polyhydroxy ketones, so you work out what the monomers, dimers or whatever else you have are.

If you simply want to test for a ketone, then you can do so as described here;

http://www.chemguide.co.uk/organicprops/carbonyls/oxidation....


A test for sugar, by the way, is to add Benedict's reagent to the sample, heat in a hot water bath and look for a colour change to orange/brown.

barley81 - 21-5-2012 at 18:34

Here's the article if you wanna read more.
http://eduframe.net/andc/biology/Sunita-Bio/carbohydrates%20...

Here is a quote from the Walmart page for ketone test strips:
Quote:
The ReliOn Ketone Test Strips are specially designed for urinalysis to check for the presence of acetoacetic acid. These strips provide a simple, fast and convenient way to detect the ketone level in urine, making them an ideal choice for low carbohydrate dieters. They provide information on carbohydrate and fat metabolism. The urine ketone testing strips contain a chemical reagent that changes color within 15-20 seconds to indicate the presence of ketone. You need to compare the color change with the color blocks provided on the label of the urinalysis reagent test strips. These ReliOn strips also help manage and safeguard against the risk of diabetic ketoacidosis. It is a safe and easy way for keeping track of changes ketone in your body according to which adjustments in your diet and/or medication can be recommended by your healthcare team.


These test strips may not test for all ketones. I have a feeling they test for "ketone bodies," since acetoacetic acid (which the information quote mentions) is one of these ketone bodies.
http://en.wikipedia.org/wiki/Ketone_bodies