DNA replication in Prokaryotes

A mesosome is a structure that was once thought to be a distinctive feature of prokaryotic cells, particularly those of bacteria. It is formed by the invagination or folding inwards of the plasma membrane. Mesosomes were initially observed in electron micrographs of bacterial cells and were proposed to play various roles in cellular processes such as DNA replication, distribution of chromosomes to daughter cells during cell division, respiration, and increasing the surface area of the plasma membrane for enzyme attachment. However, the concept of mesosomes has become highly controversial over time. Later studies suggested that mesosomes might be artifacts created by the chemical fixation techniques used to prepare cells for electron microscopy, rather than true cellular structures. This means they could result from the cell’s reaction to chemical treatments during specimen preparation, causing the plasma membrane to fold inwards artificially. Despite the initial excitement about their discovery and potential functions, the current consensus in the scientific community leans towards mesosomes being artifacts rather than functional components of the cell. As a result, they are no longer considered as playing an active role in prokaryotic cell biology in the context originally proposed.