Sliding Filament Theory

___are the thin filaments in a sarcomere.

• troponin

• tropomyosin

• actin

• myosin

___are thick filaments in a sarcomere.

• actin

• myosin

• troponin

• tropomyosin

______ are proteins that cover the myosin binding site on the actin.

• troponin-tropomyosin

• sarcomere

• sarcolemma

• sarcoplasmic reticulum

After calcium is released from the sarcoplasmic reticulum, it binds to __________

• Tropomyosin

• Actin

• Troponin

• Myosin

What happens immediately after phosphate is released from the myosin heads?

• The power stroke, which releases ADP from the myosin heads

• Calcium is released from the sarcoplasmic reticulum

• Calcium binds to troponin

• ATP attaches to actin

What happens immediately after the power stroke?

• ATP binds to myosin heads causing them to release from binding sites on actin

• phosphate is released from the myosin heads

• The sarcomere goes back to its resting state

• Calcium is resorbed into the sarcoplasmic reticulum

What happens immediately after ATP binds to myosin heads, causing them to release from binding sites on actin?

• The presence of calcium causes hydrolysis of ATP, splitting it into an ADP and a phosphate

• The power stroke

• Tropomyosin covers the binding sites on actin

• Calcium attaches to troponin causing tropomyosin to move, uncovering binding sites on actin

What happens immediately after hydrolysis splits ATP into ADP and a phosphate?

• Myosin heads bind further along on actin and the cycle repeats

• Myosin heads detach from actin

• Calcium is released from the sarcoplasmic reticulum

• The action potential stops

What happens immediately after the action potential?

• Calcium is released from the sarcoplasmic reticulum

• ADP is released from the sarcoplasmic reticulum

• Phosphate is released from the myosin head

• Myosin heads release from the binding sites on actin

Explains how the muscle fibers shorten as the actin and myosin filaments pull on each other

• threshold stimulus theory

• sliding filament theory

• neurotransmitter theory

• all or none principle