For how long, contraction of the muscles continues in sliding filament theory?

Question

For how long, contraction of the muscles continues in sliding filament theory? (A) Till ATP binds to myosin head (B) Till ADP binds to myosin head (C) Till Ca 2+ present in sarcoplasm (D) Till polymerisation of myosin head is going on

Tardigrade Admin · Accepted Answer

Sliding of actin and myosin filaments continues till the Ca 2+ ions are pumped back to the sarcoplasmic cisternae, resulting in the masking of actin filaments. This causes the return of Z-lines back to their original position, i.e. relaxation of muscle fibre.

Q. For how long, contraction of the muscles continues in sliding filament theory?

Till ATP binds to myosin head

Till ADP binds to myosin head

Till $C a^{2 +}$ present in sarcoplasm

Till polymerisation of myosin head is going on

Sliding of actin and myosin filaments continues till the $C a^{2 +}$ ions are pumped back to the sarcoplasmic cisternae, resulting in the masking of actin filaments. This causes the return of $Z$ -lines back to their original position, i.e. relaxation of muscle fibre.