List some examples of ptomaines and describe how they are formed.
A)Cadaverine, Putrescine, Indole, Skatole They are formed by the action of putrefactive bacteria on proteins.
B) Cadaverine: Cadaverine is formed by the bacterial decarboxylation of the amino acid lysine in decaying tissues. It contributes to the unpleasant odor associated with decaying bodies.

C)Putrescine: Putrescine is produced through the decarboxylation of the amino acid ornithine by bacteria during putrefaction. Like cadaverine, it contributes to the foul smell of decomposition.

D)Indole: Indole is generated by the breakdown of the amino acid tryptophan in the presence of bacteria. It is responsible for the fecal odor often associated with decomposition.