Enzyme connected with opening and closing of stomata is

Options

A. Rubisco
B. PEP carboxylase
C. `alpha `- amylase
D. pyruvic kinase

Answer

**Step-by-Step Solution:**

1. **Understanding Stomata Function**: Stomata are small openings on the surface of leaves that allow for gas exchange. Their opening and closing are primarily controlled by guard cells.

2. **Role of Guard Cells**: Guard cells are specialized cells that surround each stoma. They are unique because they contain chloroplasts, allowing them to perform photosynthesis.

3. **Photosynthesis in Guard Cells**: During photosynthesis, guard cells convert light energy into chemical energy, producing glucose.

4. **Conversion of Glucose**: The glucose produced in guard cells is converted into phosphoenolpyruvate (PEP) through a series of biochemical reactions.

5. **Enzyme Involvement**: The enzyme that facilitates the conversion of phosphoenolpyruvate into oxaloacetic acid is known as **PEP carboxylase**.

6. **Formation of Malic Acid**: The oxaloacetic acid is then converted into malic acid. This malic acid plays a crucial role in the osmotic balance within the guard cells.

7. **Potassium Ion Exchange**: The malic acid releases protons, which are exchanged with potassium ions. This exchange is vital for the turgidity of guard cells.

8. **Turgidity and Stomatal Opening**: The accumulation of potassium ions leads to the formation of potassium malate, making the guard cells hypertonic. Water then enters the guard cells, causing them to swell (turgid) and ultimately opening the stomata.

9. **Conclusion**: Therefore, the enzyme that is directly connected with the opening and closing of stomata is **PEP carboxylase**.

**Final Answer**: The enzyme connected with the opening and closing of stomata is **PEP carboxylase**.

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