Which of the following statement is false?

Options

A. `Mg^(2+)` ions are important in the green parts of plants
B. `Mg^(2+)` ions from a complex with ATP
C. `Ca^(2+)` ions are important in blood clotting
D. `Ca^(2+)` ions are not important in maintainning the regular beating of the heart

Answer

To solve the question, we need to analyze each statement provided and determine which one is false.

### Step-by-Step Solution:

1. **Analyze Statement A: "Mg²⁺ ions are important in the green part of the plant."**
- Magnesium ions (Mg²⁺) are indeed essential for plants as they are the central atom in chlorophyll, which is responsible for the green color in plants and is crucial for photosynthesis.
- **Conclusion:** This statement is **true**.

2. **Analyze Statement B: "Mg²⁺ ions form a complex with ATP."**
- Magnesium ions (Mg²⁺) bind with adenosine triphosphate (ATP) to form a complex that is necessary for ATP to be biologically active. This is a well-established fact in biochemistry.
- **Conclusion:** This statement is **true**.

3. **Analyze Statement C: "Ca²⁺ ions are important in blood clotting."**
- Calcium ions (Ca²⁺) play a crucial role in the blood coagulation process. They are essential for the activation of several proteins involved in clotting.
- **Conclusion:** This statement is **true**.

4. **Analyze Statement D: "Ca²⁺ ions are not important in maintaining the regular beating of the heart."**
- Calcium ions (Ca²⁺) are vital for the contraction of heart muscles. They help in the electrical signaling that regulates the heartbeat. Therefore, this statement is incorrect.
- **Conclusion:** This statement is **false**.

### Final Answer:
The false statement is **D: "Ca²⁺ ions are not important in maintaining the regular beating of the heart."**

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