PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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sodium and potassium
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calcium and magnesium
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sodium and calcium
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sodium and magnesium
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Detailed explanation-1: -Both calcium and magnesium are required during chemical events and muscle contraction. Hence the correct answer is option C. Note: It is to be noted that sliding of actin along with myosin, shortens the sarcomere, therefore, causing muscle contraction.
Detailed explanation-2: -Both calcium & magnesium are required for muscle contraction. Calcium binds to troponin which exposes the active sites on actin. Now myosin head can bind the active sites on actin, initiating the process of muscle contraction.
Detailed explanation-3: -The major effect of Mg2+ is to greatly reduce the rate of Ca2+ binding to the sites that bind Mg2+ and Ca2+ competitively (Ca2+-Mg2+-type sites found in troponin, parvalbumin, and myosin, which would be essentially saturated with Mg2+ in a relaxed muscle) due to the slow dissociation of bound Mg2+.