\nMechanism of muscle contraction is best explained as follows: \n1. Depolarization of Sarcolemma - The central nervous system(CNS) sends a signal to the neuromuscular junction, which is the point of contact between the sarcolemma of the muscle fibre and the motor neuron. It stimulates the release of a neurotransmitter known as acetylcholine which sets the action potential in the sarcolemma.
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2. Release of calcium ions - The above action potential reaches the sarcolemma to the sarcoplasmic reticulum through the t-Tubule, and triggers the release of the calcium ions in the sarcoplasm.
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3. Confirmation change in the Actin Filaments- The calcium ions bind to the tropomyosin and troponin that are located on the actin myofilaments, which causes a modification in the three-dimensional structure of the actin-troponin-tropomyosin complex. Thus, the active site for myosin located on the actin filament is exposed.
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4. Activation of Myosin heads - When the myosin heads get activated, the hydrolysis of ATP occurs. It releases energy that causes the binding of myosin heads to the active sites on the actin filaments, forming a cross-bridge in between them.
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\n5. Sliding of Actin Filaments over Myosin heads- Formation of cross-bridge causes the myosin head to rotate which pulls the actin filaments to the centre of the A-band and the H zone disappears. The z-line that is attached to the actin filaments is also pulled inwards, which results in the contraction of the sarcomere. The I-band also shortens during the process of contraction, whereas the A-band maintains its length.
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\n"},"comment":{"@type":"Comment","text":"Energy is needed for the muscles to contract. Calcium ion plays an important role in muscle contraction."},"encodingFormat":"text/markdown","learningResourceType":"Practice problem","suggestedAnswer":[],"text":"Describe the sliding filament theory of skeletal muscle contraction."},"name":"Quiz on Locomotion and Movement","typicalAgeRange":"10-17","url":"https://www.embibe.com/questions/Describe-the-sliding-filament-theory-of-skeletal-muscle-contraction./EM7681269"}
Odisha Board Solutions for Exercise 19: SAMPLE QUESTIONS
Author:Odisha Board
Odisha Board Biology Solutions for Exercise - Odisha Board Solutions for Exercise 19: SAMPLE QUESTIONS
Attempt the free practice questions from Exercise 19: SAMPLE QUESTIONS with hints and solutions to strengthen your understanding. Bureau's Higher Secondary Biology Volume-1 solutions are prepared by Experienced Embibe Experts.
Questions from Odisha Board Solutions for Exercise 19: SAMPLE QUESTIONS with Hints & Solutions