What is the difference between an aldose and a ketose?
An aldose contains an aldehyde group; a ketose contains a ketone group,
The ending -ose tells you that both aldoses and ketoses are carbohydrates.
Carbohydrates are really just polyhydroxyaldehydes (aldoses) or polyhydroxyketones (ketoses).
So, for a carbohydrate to be an aldose it needs an aldehyde group and, to be a ketose, it needs a ketone group.
In the structures below, the aldehyde and ketone carbonyl groups are marked in pink.
Examples of aldoses are glucose
Examples of ketoses are fructose