Aldehydes and ketones:

Aldehydes

An aldehyde is an organic compound consisting of a formyl group. This functional group, along with the structure R-CHO, contains a carbonyl center (a carbon double bonded to oxygen) bonded to hydrogen and an R group that is any generic alkyl or side chain. The group without R is known as the aldehyde group or formyl group. Aldehydes are diferent from ketones in that the carbonyl is located at the end of a carbon skeleton rather than among the two carbon atoms. Aldehydes are general in organic chemistry. Several fragrances are aldehydes.

ketones

A ketone is an organic compound along with the structure RC (=O) R', in which R and R' can be a variety of carbon-containing substituents, in chemistry. Ketones feature a carbonyl group (C=O) bonded to 2 other carbon atoms. Several ketones are known and many are of great significance in industry and in biology. Instances include many sugars (ketoses) and the industrial solvent acetone.

         Figure: Aldehydes and ketones