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Assertion : Ca^(2+) plays important role...

Assertion : `Ca^(2+)` plays important role in the muscle contraction.
Reason : `Ca^(2+)` Combines with troponin chain, displacing tropomyosin allowing the myosin head part to combine with actin to from actomyosin complex .

A

IF both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark

B

If Both Assertion & Reason are true but the reason is not the correct exlanation of the assertion then mark

C

IF Assertion is true statement but Reason is false then mark

D

If both Assertion and Reason are false statements then joint

Text Solution

AI Generated Solution

The correct Answer is:
To solve the assertion and reason question regarding the role of calcium ions in muscle contraction, we can break it down into the following steps: ### Step-by-Step Solution: 1. **Understanding the Assertion**: - The assertion states that `Ca^(2+)` plays an important role in muscle contraction. This is true because calcium ions are crucial for initiating the contraction process in muscle fibers. 2. **Understanding the Reason**: - The reason explains that `Ca^(2+)` combines with the troponin chain, which displaces tropomyosin. This action allows the myosin head to bind with actin, forming the actomyosin complex. This is also true and accurately describes the biochemical process that occurs during muscle contraction. 3. **Mechanism of Muscle Contraction**: - When a muscle receives a stimulus, it travels through T-tubules to the sarcoplasmic reticulum, which releases calcium ions. - These calcium ions bind to troponin C (a component of the troponin complex), causing a conformational change in troponin. - This change in troponin causes tropomyosin to move away from the binding sites on actin, exposing them. - The myosin heads, which have ATP bound to them, can now attach to the exposed binding sites on actin, forming the actomyosin complex. - This interaction is essential for muscle contraction to occur. 4. **Conclusion**: - Since both the assertion and reason are true, and the reason correctly explains the assertion, we can conclude that the assertion and reason are both valid statements about the role of calcium in muscle contraction. ### Final Answer: Both the assertion and the reason are true, and the reason provides the correct explanation for the assertion.
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