单糖本质上是脂族的多羟基醛和酮，即HOCH2 - (CHOH) 2 - CHO和HOCH 2 - (CHOH) n - 1 - C： O - CH 2 OH，分别称为醛糖和酮糖。

The simple sugars monosaccharides0 are basically aliphatic polyhydroxy aldehydes and ketones: HOCH2 - CHOH n-CHO and HOCH2 - CHOOH n-1-C-O-Ch2OH, called "aldoses" and "ketoses," respectively.

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