Sliding filament theory

Front

What is the sliding filament theory?

Back

The sliding filament theory explains how muscles contract by the sliding of actin filaments over myosin filaments, resulting in muscle shortening.

Front

What is the role of Ca2+ in muscle contraction?

Back

Ca2+ binds to troponin, causing a conformational change that allows myosin to bind to actin, initiating contraction.

Front

What is the all-or-none response in muscle fibers?

Back

The all-or-none response means that when a muscle fiber is stimulated, it contracts completely or not at all.

Front

Where is Ca2+ stored in muscle cells?

Back

Ca2+ is stored in the sarcoplasmic reticulum.

Front

What is needed for muscle contraction to continue?

Back

Ca2+ and ATP are needed for muscle contraction to continue.

Front

What causes the force of muscle contraction?

Back

The force of contraction is caused by the movement of actin filaments.

Front

What happens to ATP during muscle contraction?

Back

ATP binds to myosin, allowing it to detach from actin after a power stroke.

Front

What is the function of tropomyosin in muscle contraction?

Back

Tropomyosin blocks the binding sites on actin, preventing contraction until Ca2+ binds to troponin.

Front

What initiates the muscle contraction process?

Back

Nerve stimulation initiates the muscle contraction process by releasing Ca2+ from the sarcoplasmic reticulum.

Front

What is the power stroke in muscle contraction?

Back

The power stroke is the movement of myosin heads pulling actin filaments toward the center of the sarcomere.