Part A- In Skeletal muscle sarcomeres, the H zone is in the middle and bounded o
ID: 164892 • Letter: P
Question
Part A- In Skeletal muscle sarcomeres, the H zone is in the middle and bounded on each side by a Z line. During contraction, the Z lines on either side move in opposite directions toward the H zone. Myosin, however, can crawl along an actin filament in only one direction. How can you reconcile movements of Z lines in opposite directions with the unidirectional movement of myosin along an actin filament?
Drag the terms on the bottom to the approproate blanks on the right to complete the sentences. Not all terms will be used.
The myosin thick filaments are assembled with the rodlike tail domin located ______ of the filament and the globular heads located ______ of the filament pointing ______ the center. Therefore, the globular myosin _______ at each end of the thick filament have _______. This reuslts in the movemtn of the actin filaments in _______ so that actin filaments from each Z line are drawn _______ the center of the sarcomere.
Options: Opposite directions, The same direction, The same polarity, Tails, Away from, Heads, Opposite polarities, To, At the center, At the ends
Explanation / Answer
The myosin thick filaments are assembled with the rodlike tail domain located At the center of the filament and the globular heads located At the ends of the filament pointing Away from the center. Therefore, the globular myosin Heads at each end of the thick filament have Opposite polarities. This results in the movement of the actin filaments in Opposite directions so that actin filaments from each Z line are drawn To the center of the sarcomere.