- Exam
- NEET
- Subject
- Zoology
- Chapter
- Locomotion and Movement
NEET · Zoology · Locomotion and Movement
What is the significance of the binding of calcium ions to a...
Options
- AIt leads to the binding of myosin to the actin filaments
- BIt helps in ATP production
- CIt masks the active sites for myosin
- DIt causes the release of ADP and Pi from myosin
Correct answer
A. It leads to the binding of myosin to the actin filaments
Step-by-step solution
Muscle contraction is initiated by a signal sent by the central nervous system (CNS) via a motor neuron.The junction between a motor neuron and the sarcolemma of the muscle fibre is called the neuromuscular junction or motor-end plate.When a neural signal reaches the neuromuscular junction, it releases a neurotransmitter (Acetylcholine) which generates an action potential in the sarcolemma. The binding of calcium ions to a subunit of troponin causes the removal of the masking of the active sites for myosin. This allows the myosin head to bind to the exposed active sites on actin, forming a cross bridge and causing contraction of the muscle.