Similarities shared between mitochondria and chloroplasts include having both an inner and outer membrane and a phospholipid bilayer. Both organelles produce energy, in the form of ATP, for the cell through chemiosmosis. Mitochondria and chloroplasts have their own DNA, and reproduce independently from their host cells.
Mitochondria is found in eukaryotic cells, which include fungi, animals, plants and unicellular organisms. The energy it generates for its host cell, ATP, comes from glucose produced during cellular respiration. Chloroplasts are found in plant cells and produce ATP through photosynthesis. Using this process, chloroplasts produce glucose for storage in the plant.
In mitochondria and chloroplasts, similar enzymes and co-enzymes that aid in vital processes, such as electron transport and ATP production, are found. These enzymes are used differently in each organelle. However, the DNA present in each organelle perform the same functions for cell replication. The American Society for Microbiology states that scientists believe that both mitochondria and chloroplasts evolved from bacteria and were once free living prokaryotes without a nucleus and/or organelles. At some point, these prokaryotes found larger cells to become their host. While mitochondria entered these larger cells as an invader, it is believed that chloroplasts found their way into larger cells as food.