Mesosomes are convoluted membranous structure formed in a prokaryotic cell by the invagination of the plasma membrane. It has the follwing functions -

1. The extensions help in the synthesis of the cell wall and replication of DNA. They also help in the equal distribution of chromosomes into the daughter cells.

2. It also increases the surface area of the plasma membrane to carry out various enzymatic activities.

3. It helps in secretion processes as well as in bacterial respiration.