Arrange the following steps of muscle fiber contraction in the correct sequence.
1) The muscle impulse reaches the sarcoplasmic reticulum and calcium is released.
2) Thin filaments are pulled over the thick filaments.
3) Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites.
4) The impulse arrives at the synapse and travels through the transverse tubules.
5) The muscle fiber shortens and contracts.
6) Myosin heads bind to exposed active sites on actin, forming cross-bridges.
7-30-2013
A) 4, 1, 3, 5, 6, 2
B) 4, 1, 3, 2, 6, 5
C) 4, 1, 3, 6, 2, 5
D) 4, 3, 6, 2, 5, 1

Question

Quizplus · Accepted Answer

The correct sequence of muscle fiber contraction is:
1) The impulse arrives at the synapse and travels through the transverse tubules (4).
2) The muscle impulse reaches the sarcoplasmic reticulum and calcium is released (1).
3) Calcium floods the sarcoplasm and binds to troponin molecules leaving active sites (3).
4) Myosin heads bind to exposed active sites on actin, forming cross-bridges (6).
5) Thin filaments are pulled over the thick filaments (2).
6) The muscle fiber shortens and contracts (5).
Therefore, the correct choice is C) 4, 1, 3, 6, 2, 5.

Arrange the Following Steps of Muscle Fiber Contraction in the Correct