Oxidation of Monosaccharides - Video Tutorials & Practice Problems

Oxidation of Monosaccharides Concept 1

In this video, we're gonna take a look at the oxidation of monosaccharide. Now recall that in Benedict's test, an aldehyde undergoes oxidation to a carbolic acid and forms a brick red precipitate. Here, we're going to say that our all dose monosaccharide. So aldehyde sugars produce what we call an Aldon acid. And all donic acids are sugar acids. And again, this happens upon oxidation. And a key takeaway from here is that we're changing the ending of our sugar name from O to ony acid. If we take a look here at this reaction, we have D ribose, which is a typical adult sugar. So we have an aldehyde here. We're using copper two ion to oxidize this Aldo sugar. We oxidize it into a carbolic acid group. And now we're gonna still be DD sugar. It's still gonna be RBE. And remember we're changing the OS to on acid. So it becomes ribon acid, the brick red precipitate. It happens in the form of copper one oxide here. So this is just a by-product which would be our, our solid brick precipitate. Now, here, in addition to this, we have what's called a reducing sugar. This is a carbohydrate that produces a sugar acid upon oxidation like d ribose. And we're gonna say here, Benedict's test can be used to detect are reducing sugar in solution. So just remember in Benedict's task, we're basically changing a aldose sugar into a carbolic acid group. This transitions transitions away from an aldose sugar to an Aldon acid or sugar acid.

Oxidation of Monosaccharides Example 1

Here in this example question, it says draw and name the product of the reaction when D gulose is treated with the basic copper two solution. So we're undergoing Benedict's test. Now remember under Benedict's test, we're gonna transform our aldose sugar into a sugar acid. This happens by changing the aldehyde group into a carboy acid group through oxidation. So here that aldehyde group is now going to be a carbolic acid. Everything else would stay the same. It's just that group that gets changed into a carbolic acid. So all these hs in hydroxyl groups are gonna stay in the same position. Remember when it comes to our sugar acid, we transform the os ending to ony acid. So this would be D GIC acid. So this would be its structure as a carbolic acid or sugar acid. And D GIC acid would be its name.

Ketoses as Reducing Sugars Concept 2

Now, besides all those sugars, we can say here that keto sugars can also be reducing sugars. We're gonna say in basic solutions, ketones undergo rearrangement to form all doses. So here we have d fructose, d fructose represents a ketose. This ketos itself can undergo a rearrangement where it was a key Toone here. But now it is an aldehyde group. The number of carbons stay the same. It's just that we've changed, going from going from a ketone to an aldehyde. So here now it is an aldose sugar. We've transitioned from being def fructose to d glucose because of this possibility of rearrangements with keto sugars. We can say that all all dose in ketose monosaccharide are reducing sugars in basic solutions. So keep this in mind reducing sugars are not only limited to all those sugars. Keto sugars can be included as well.

Ketoses as Reducing Sugars Example 2

Which of the following statements is incorrect. About oxidation of monosaccharide. All monosaccharide are reducing sugars. Yes, that's true. That's because all those sugars automatically can be oxidized in basic solutions into sugar acids. Ketosis can rearrange to become all dose sugars which again can be oxidized into sugar acids. Ketosis undergo rearrangement to produce all doses in basic solution. That is true. Some keto or Keto's monosaccharide are reducing sugars. This is incorrect. It's not some, it's all because those keto sugars can undergo a rearrangement to become all those sugars. And all those, all those sugars can be oxidized. All reducing sugars produce a brick red precipitate in Bendix test. Yes, they do that. Brick red precipitate is copper one oxide. So this is true. So out of my four statements, the only one that's incorrect is option C

Write common names for the reduction and oxidation products of D-allose.

• A. D-allosol and D-allonic acid
• B. D-allitol and D-allinic acid
• C. D-allitol and D-allonic acid
• D. D-allositol and D-allitonic acid

Complete the following reduction/oxidation reaction of D-idose.

• A.
• B.
• C.
• D.