PHYSIOLOGY
MUSCLE STRUCTURE FUNCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Connections
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Cross-connections
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Cross-bridges
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Power stroke
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Detailed explanation-1: -The globular heads of myosin bind actin, forming cross-bridges between the thick and thin filaments. It is important to note that the orientation of myosin molecules in the thick filaments reverses at the M line of the sarcomere .
Detailed explanation-2: -These MYOSIN heads are also commonly referred to as CROSS-BRIDGES. The MYOSIN HEAD has several important characteristics:-it has ATP-binding sites into which fit molecules of ATP. ATP represents potential energy.-it has ACTIN-binding sites into which fit molecules of ACTIN.
Detailed explanation-3: -The first step in the process of contraction is for Ca++ to bind to troponin so that tropomyosin can slide away from the binding sites on the actin strands. This allows the myosin heads to bind to these exposed binding sites and form cross-bridges.