Name the enzyme which acts on carbonic acid in living cells.

Explanation

**Step-by-Step Solution:**

1. **Identify the Enzyme**: The question asks for the name of the enzyme that acts on carbonic acid in living cells.

2. **Recall the Function of the Enzyme**: The enzyme that acts on carbonic acid is known to facilitate the conversion of carbonic acid into its dissociated forms, which are protons (H⁺) and bicarbonate ions (HCO₃⁻).

3. **Name the Enzyme**: The enzyme responsible for this reaction is called **carbonic anhydrase**.

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