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25.9 Ketoses. Ketoses. Ketoses are carbohydrates that have a ketone carbonyl group in their open-chain form. C-2 is usually the carbonyl carbon. CH 2 OH. CH 2 OH. CH 2 OH. O. O. O. H. OH. H. OH. HO. H. OH. H. OH. H. HO. H. OH. H. CH 2 OH. CH 2 OH. CH 2 OH. Examples.
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Ketoses • Ketoses are carbohydrates that have a ketone carbonyl group in their open-chain form. • C-2 is usually the carbonyl carbon.
CH2OH CH2OH CH2OH O O O H OH H OH HO H OH H OH H HO H OH H CH2OH CH2OH CH2OH Examples D-Ribulose L-Xyulose D-Fructose
Deoxy Sugars • Often one or more of the carbons of a carbohydrate will lack an oxygen substituent. Such compounds are called deoxy sugars.
CH O CH O H OH H H OH OH H H OH H H HO H HO CH2OH CH3 Examples 2-Deoxy-D-ribose 6-Deoxy-L-mannose
Amino Sugars • An amino sugar has one or more of its oxygens replaced by nitrogen.
HOCH2 O HO HO OH NH O C CH3 Example N-Acetyl-D-glucosamine
OH H3C O NH2 HO Example L-Daunosamine
Branched-Chain Carbohydrates • Carbohydrates that don't have a continuous chain of carbon-carbon bonds are called branched-chain carbohydrates.
CH O OH CH3 H OH H3C O HO CH2OH NH2 HO CH2OH Examples D-Apiose L-Vancosamine