Which enzymes are found in the cellular membrane of a prokaryotic cell to produce energy?

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Prokaryotic cells lack membrane bound organelles and the process of respiration occurs in an area known as the mesosome within the cytoplasm. The mesosome is created as the plasma membrane folds inward, and within this region are respiratory enzymes which function within an electron transport chain. However, not all prokaryotic...

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Prokaryotic cells lack membrane bound organelles and the process of respiration occurs in an area known as the mesosome within the cytoplasm. The mesosome is created as the plasma membrane folds inward, and within this region are respiratory enzymes which function within an electron transport chain. However, not all prokaryotic cells contain mesosomes.

In the membrane are proteins that can function as carrier molecules to allow electrons to flow in a series of redox reactions. This is coupled with pumping protons against their gradient. This creates a proton motive force that is used to drive cellular work including regeneration of ATP from ADP plus inorganic phosphate as the protons fall down their concentration gradient through an enzyme called ATP synthase.

The enzymes involved in prokaryotic cellular respiration are embedded in the cell membrane and include NADH dehydrogenase complex, various cytochromes and the enzyme cytochrome oxidase complex, co-enzyme Q. The enzyme ATP synthase uses the proton motive force to synthesize ATP from ADP plus inorganic phosphate. These enzymes, co-enzymes and carrier molecules are located in the inner membrane of bacteria cells.

The flow of electrons in these cells proceeds in the following direction-- from organic compounds from food, to the carrier molecule NADH, to the electron transport chain and to oxygen, the final electron accceptor. This is for aerobic prokaryotic cells. 

I have included a nice diagram of the membrane of prokaryotic cells containing the various enzymes I have described.

 

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