Question

Which of the following statements is not true regarding contraction?

• A. Z discs are drawn toward each other
• B. Acetylcholinesterase is released from the synaptic end bulbs of a neuron
• C. Movement is caused by the power stroke of the myosin cross bridges.
• D. $C{a}^{+}$ ions and ATP are required for the muscle to contract

Answer 1

The correct option is B Acetylcholinesterase is released from the synaptic end bulbs of a neuron

• Myofibril activity is required for muscle contraction on the molecular level.
  
• When ATP binds to myosin, it separates from the actin of the myofibril, which causes a contraction.
  

Z discs move towards each other.

• The muscle contraction cycle is triggered by calcium ions binding to the protein complex troponin, exposing the active-binding sites on the actin.
  
• ATP then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.
  

So, the correct option is 'Acetylcholinesterases is released from the synaptic end bulbs of a neuron'.