SLIDING FILAMENT THEORY OF MUSCLE CONTRACTION

What causes the filaments to slide in muscle contraction?

• Release of calcium ions

• Presence of troponin and tropomyosin

• Interaction of myosin and actin molecules

• Detachment of myosin from actin molecule

What is the energy source for muscle relaxation?

• Adenosine Triphosphate (ATP)

• Calcium ions

• Myosin crossbridges

• Troponin and tropomyosin

What is the sliding filament theory of muscle contraction?

• Muscles contract by shortening

• Muscles push on the bones

• Filaments overlap and slide relative to each other

• Filaments detach and reattach in rapid succession

What is the trigger mechanism for the sliding filament process?

• Release of myosin crossbridges

• Presence of troponin and tropomyosin

• Release of calcium ions

• Detachment of myosin from actin molecule

What is the function of myosin crossbridges in muscle contraction?

• To release calcium ions

• To facilitate interaction of myosin and actin molecules

• To detach myosin from actin molecule

• To create obstacles for muscle contraction

What is the role of troponin and tropomyosin in muscle contraction?

• To release calcium ions

• To facilitate interaction of myosin and actin molecules

• To detach myosin from actin molecule

• To create obstacles for muscle contraction

What happens to the sarcomere during muscle contraction?

• It remains the same length

• It lengthens

• It shortens

• It detaches from the muscle fibre

___are regulatory proteins that cover the myosin binding site on the actin.

• troponin-tropomyosin

• sarcomere

• sarcolemma

• sarcoplasmic reticulum

Calcium binds to ___of the troponin-tropomyosin complex.

• troponin

• tropomyosin

• actin

• myosin

Calcium is stored in the ___.

• sarcoplasm

• sarcolemma

• sarcoplasmic reticulum

• transverse tubules