PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Actin and myosin fibers
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neuron and muscle
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mitochondria and actin
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None of the above
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Detailed explanation-1: -The globular heads of myosin bind actin, forming cross-bridges between the thick and thin filaments.
Detailed explanation-2: -There are two factors that are necessary in cross bridge formation. These two factors are an elevated concentration of calcium because cross bridges cannot form without calcium changing the shape of troponin. An adequate supply of ATP is also necessary becaue this proces requires energy.
Detailed explanation-3: -Figure 1: A cross-bridge forms between actin and the myosin heads triggering contraction.
Detailed explanation-4: -Control of muscle tension. Neural control initiates the formation of actin-myosin cross-bridges, leading to the sarcomere shortening involved in muscle contraction. These contractions extend from the muscle fiber through connective tissue to pull on bones, causing skeletal movement.
Detailed explanation-5: -Troponin binds to tropomyosin and helps to position it on the actin molecule; it also binds calcium ions. To enable a muscle contraction, tropomyosin must change conformation, uncovering the myosin-binding site on an actin molecule and allowing cross-bridge formation.