Question

question 4 (1.25 points)
which of the following is/are mismatched?

1. muscle contraction energy source - adp
2. ca²+ - myosin binding
3. neurons - release troponin
4. muscle - connective tissue
5. all are mismatched
6. none are mismatched

Explanation:

• Option 1: The energy source for muscle contraction is ATP (adenosine triphosphate), not ADP (adenosine diphosphate). ADP is a product of ATP hydrolysis.
• Option 2: \(Ca^{2+}\) binds to troponin, not myosin. When \(Ca^{2+}\) binds to troponin, it causes a conformational change that exposes the myosin - binding sites on actin.
• Option 3: Neurons release neurotransmitters (e.g., acetylcholine at the neuromuscular junction). Troponin is a protein complex found in muscle cells, not released by neurons.
• Option 4: Muscle is surrounded by connective tissue. For example, epimysium (surrounds the whole muscle), perimysium (surrounds muscle fascicles), and endomysium (surrounds individual muscle fibers). So, this is a correct match.

Answer:

1. Muscle contraction energy source - ADP, 2) \(Ca^{2+}\) - myosin binding, 3) Neurons - release troponin.