Have you ever thought that although some organelles are found in different types of cells, they can share many common features? If you still haven't guessed what I am talking about, let me say it: mitochondria and chloroplasts. Before discussing their similarities, let's first take a look at both organelles.
In general, mitochondria, which are bean-shaped or oval, are found in all living organisms that perform aerobic respiration, except for prokaryotes and mature red blood cells. It is composed of two membranes: an outer membrane and an inner membrane. The folds, called cristae, are filled with a fluid called the matrix, which houses DNA, RNA, ribosomes, and respiratory enzymes. Mitochondria's essential task is to produce energy for the cell.
Chloroplasts, which are rectangular or oval, consist of stroma, grana, and intergranal lamellae, and are one of the three types of plastids. Chloroplasts are green because they contain chlorophyll, and are found in some protists as well as all green parts of plants. DNA, RNA, ribosomes, enzymes, starch, and lipids are found in the stroma, whereas chlorophyll is located in the grana. Like mitochondria, it is also composed of an outer and an inner membrane. Chloroplast's essential task is to perform photosynthesis.
Now it's time to move on to their common features. Both organelles have a double membrane. They are involved in ATP synthesis and ATP consumption through processes called phosphorylation and dephosphorylation. They also have an electron transport system (ETS) — while ETS in mitochondria functions in the final stage of cellular respiration, it is involved in the light reactions of photosynthesis in chloroplasts.
Both mitochondria and chloroplasts are absent in prokaryotes, whereas they are present in eukaryotic cells. They have DNA, RNA, ribosomes, and also replicate themselves. They have energy transformation processes (mitochondria: chemical energy transformation / chloroplast: light energy transformation). And finally, they synthesize proteins and enzymes.
So far, I have told you all the common features of mitochondria and chloroplasts. The differences between the two remain, but since my goal is to clearly explain their common characteristics, I won't go into that topic for now. Thank you for reading, take care of yourselves, and don't forget to follow STEMxFuture for more science content! (Source: Biyoloji Portalı)