What is released as a phosphate ion during the action of a phosphatase?

The action of a phosphatase involves the removal of a phosphate group from a substrate, typically as part of a biochemical reaction. This enzymatic activity specifically releases inorganic phosphate, which is often referred to simply as a phosphate ion. Phosphatases play a vital role in various metabolic pathways, including the regulation of signal transduction and energy metabolism.

When the phosphatase enzyme acts on a substrate that has a phosphate group, it catalyzes the hydrolytic removal of that phosphate. This process liberates the phosphate ion, which can then participate in other biochemical reactions or regulatory processes within the cell.

In the context of the other choices, ATP and ADP are nucleotides that store and transfer energy in cells, but they do not constitute the phosphate ion released by phosphatase activity. Glucose is a simple sugar that serves as a primary energy source in cells, but it is unrelated to the function of a phosphatase regarding phosphate release. Therefore, the correct understanding is that a phosphate ion is indeed released as a product of the action of a phosphatase, making it the right answer.