Answers:
1) - COOH
2) carboxyl group
The organic acids contain the carboxyl group: - COOH.
Fats are structures composed by fatty acids. Fatty acids are long aliphatic chains with a carboxyl group at the end.
Aminoacids are chains that contains amine group (NH2) at one end and the carboxyl group at the other end.
Then both aminoacids and fatty acids contain the carboxyl group (-COOH) at one end.
