Sliding Filament Theory of Muscle Contraction

Front

What slides inward during muscle contraction?

Back

Actin slides inward during muscle contraction.

Front

What are thin filaments in muscle contraction?

Back

Actin is a thin filament.

Front

What gets shorter during muscle contraction?

Back

None of the filaments (actin, myosin, troponin-tropomyosin) get shorter; they slide past each other.

Front

What provides energy for muscle contraction and relaxation?

Back

ATP (Adenosine Triphosphate) provides energy for muscle contraction and relaxation.

Front

What are thick filaments in muscle contraction?

Back

Myosin is a thick filament.

Front

What is the role of troponin in muscle contraction?

Back

Troponin regulates muscle contraction by controlling the interaction between actin and myosin.

Front

What is the function of tropomyosin in muscle contraction?

Back

Tropomyosin blocks the binding sites on actin for myosin, preventing contraction when the muscle is relaxed.

Front

What is the sliding filament theory?

Back

The sliding filament theory explains how muscles contract by the sliding of actin and myosin filaments past each other.

Front

What happens to the sarcomere during muscle contraction?

Back

The sarcomere shortens as actin filaments slide over myosin filaments.

Front

What is the role of calcium ions in muscle contraction?

Back

Calcium ions bind to troponin, causing a conformational change that allows myosin to bind to actin.