The part of the cell that is a major site of ATP synthesis and scattered throughout the cell is the mitochondria.

Here's why:

* ATP Synthesis: Mitochondria are often called the "powerhouses of the cell" because they are the primary site of ATP (adenosine triphosphate) production. ATP is the cell's main energy currency.

* Scattered Throughout the Cell: Mitochondria are not fixed in one place but are found throughout the cytoplasm of eukaryotic cells. This allows them to be close to the areas where energy is needed.

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