ATP (Adenosine Triphosphate) is both intracellular and extracellular. While it is primarily known for its role inside cells, it is also found outside cells.
Here's a breakdown:
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Intracellular ATP: ATP is primarily an intracellular molecule, serving as the main energy currency within cells. Its concentration inside cells is significantly higher.
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Extracellular ATP (eATP): ATP can also be found in the extracellular environment. It is actively released from cells in response to various stimuli, such as tissue damage or cellular stress. However, the concentration of eATP is much lower than intracellular ATP.
| Feature | Intracellular ATP | Extracellular ATP (eATP) |
|---|---|---|
| Location | Inside cells | Outside cells |
| Primary Function | Energy currency | Signaling molecule |
| Concentration | 3-10 mM | ~10 nM |
| Release Mechanism | N/A | Released upon stress |
According to provided reference [1], the concentration of cellular ATP is 3 to 10 mM, while the concentration of extracellular ATP is only about 10 nM.
