Which of the following structures perform the function of mitochondria in bacteria?

Mesosomes is a characteristic invaginations of bacterial cell membrane that develop as an ingrowth from plasma membrane. It consists of vesicles, tubules and lamellae. Mesosomes may be septal or lateral. Septal mesosome connects nucleoid with plasma membrane and assists in replication and septum formation during cell division. Lateral mesosome is not connected with nucleoid and contains respiratory enzymes and performs functions similar to eukaryotic mitochondria and hence is also called chondrioid. They also increase the surface area of plasma membrane and enzymatic content.