Arrange the following events of muscle contraction in the correct chronological order: I. Binding of calcium with a subunit of troponin on actin filaments. II. Release of neurotransmitter at the neuromuscular junction. III. Binding of myosin head to exposed active sites on actin. IV. Generation of action potential in the sarcolemma. V. Release of calcium ions into the sarcoplasm. VI. Removal of masking of active site

Step-by-step solution

The correct chronological sequence of events during muscle contraction according to the sliding filament theory is: 1. A neural signal reaches the neuromuscular junction and releases a neurotransmitter (acetylcholine) (II). 2. The neurotransmitter generates an action potential in the sarcolemma (IV). 3. The action potential spreads through the muscle fibre and causes the release of calcium ions into the sarcoplasm from the sarcoplasmic reticulum (V). 4. The increase in calcium level leads to the binding of calcium