Question

Which of the following statements is false?

• A. Mg²+ ions form a complex with ATP
• B. Ca²+ ions are important in blood clotting
• C. Ca²+ ions are not important in maintaining the regular beating of the heart
• D. Mg²+ ions are important in the green parts of the plant

Answer 1

The correct option is C

Ca²+ ions are not important in maintaining the regular beating of the heart

The correct option is B.

Explanation of the correct option:

1. The atria and ventricles of the heart work together by alternately contracting and relaxing to pump blood throughout the body.
2. The contraction of the atria and ventricles makes a heartbeat.
3. The heartbeat makes a lubb-dubb sound.
4. Calcium ions are crucial in regulating the electrical signal that coordinates the functioning of the heart.
5. Calcium ions enter the cardiac muscles during each heartbeat and generate the electrical signal that results in muscle contraction.

Explanation of the incorrect options:

Option A:

1. Adenosine triphosphate (ATP) is an energy molecule that is utilized for the metabolic activities of the cell.
2. ATP needs to bind to magnesium ions to transform into a biologically functional form.

Option C:

1. Clotting of blood is a vital process that prevents excessive blood loss during injuries.
2. Calcium ions are required to activate the prothrombin activator enzyme which then converts prothrombin into thrombin.
3. The thrombin enzyme converts fibrinogen into fibrin which helps the blood clot.

Option D:

1. The magnesium ion is the central atom of the chlorophyll molecules.
2. It helps absorb light and sustains the electrons in an excited state so that electron transport can occur.

Final answer: Ca²+ ions are not important in maintaining the regular beating of the heart is a false statement.