Yes, animal cells contain mitochondria. Mitochondria are organelles that are often referred to as the "powerhouses of the cell" because they generate most of the cell's energy. They are found in eukaryotic cells, which include animal cells, plant cells, and fungal cells. Mitochondria have a double membrane structure, with the outer membrane being smooth and the inner membrane being highly folded into cristae. The cristae increase the surface area of the inner membrane, which is where the electron transport chain is located. The electron transport chain is responsible for generating ATP, the cell's energy currency.