What is the source of energy for muscle contraction?

Explanation

**Step-by-Step Solution:**

1. **Identify the Source of Energy**: The primary source of energy for muscle contraction is adenosine triphosphate (ATP).

2. **Role of Myosin**: Each myosin molecule has a specific part known as the myosin head, which contains an enzyme called myosin ATPase.

3. **Enzymatic Action**: In the presence of calcium ions (Ca²⁺) and magnesium ions (Mg²⁺), the myosin ATPase enzyme facilitates the breakdown of ATP.

...