In skeletal muscle contraction and relaxation, calcium ions
A) bind to myosin myofilaments.
B) are returned to the sarcoplasmic reticulum by active transport.
C) are released from the T tubules by active transport.
D) provide the energy for muscle contraction.
E) have both bind to myosin myofilaments and are returned to the sarcoplasmic reticulum by active transport as normal properties.

Question

Quizplus · Accepted Answer

During skeletal muscle relaxation, calcium ions are actively transported back into the sarcoplasmic reticulum by the protein pump SERCA. This allows for the myosin and actin myofilaments to dissociate, ending the contraction.

In Skeletal Muscle Contraction and Relaxation, Calcium Ions