Botany online 1996-2004. No further update, only historical document of botanical science!
The oxidation of an aldehyde-group results in an organic acid. Its most important feature is the carboxyl-group (-COOH). Carboxyl groups are able to dissociate.
Especially in plant cells, an extraordinary large collection of organic acids can be found. Here, too, is it distinguished between compounds that harbour one or more -COOH group, have double bonds or additional functional groups (like amino acids).