TBR carbohydrate section

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pizza1994

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Aldoses have one less sterogenic carbon in their straight chain form than ketohexoses with the same number of carbons.

is this statement wrong?

I thought ketohexoses have one less sterocenter than aldoses.....
 
Yes, this statement on it's own (out of context) appears to be backwards. To visualize this, look at the structure of glucose (an aldohexose) and fructose (a ketohexose). They both have 6 carbons and glucose has 4 stereocenters (or stereogenic carbons) while fructose only has 3 (due to the ketone functionality).
 
Aldoses have one less sterogenic carbon in their straight chain form than ketohexoses with the same number of carbons.

is this statement wrong?

I thought ketohexoses have one less sterocenter than aldoses.....

That sentence is backwards ( a typo). If you read the next two lines of the explanation, it states that a stereogenic center is lost when the aldose is converted into a ketose, which is why choice A is eliminated.
 
Yes, this statement on it's own (out of context) appears to be backwards. To visualize this, look at the structure of glucose (an aldohexose) and fructose (a ketohexose). They both have 6 carbons and glucose has 4 stereocenters (or stereogenic carbons) while fructose only has 3 (due to the ketone functionality).
great 🙂 thanks
 
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