Sliding Filament Theory

What is the mechanism by which muscles are thought to contract at a cellular level?

• Sliding Filament Theory
• Nerve Impulse
• Calcium
• Acetylcholine

Which organelles are cylindrical and found within muscle fibers?

• Myofibrils
• Actin
• Myosin
• Crossbridges

What is the network of tubules and channels where calcium is stored in the muscle fiber?

• Sarcoplasmic Reticulum
• ATP
• Tropomyosin
• Sarcomere

Which proteins are found in bundles within the myofibrils of muscle fibers?

• Actin and Myosin
• Tropomyosin and ATP
• Calcium and Acetylcholine
• Nerve Impulse and Crossbridges

What is the chemical that causes depolarization when a nerve impulse arrives at the muscle?

• Acetylcholine
• Calcium
• Troponin
• ATP

Which protein changes shape when calcium binds to it, allowing myosin to attach to actin?

• Troponin
• Tropomyosin
• Actin
• Myosin

What releases energy during muscular contraction to enable myosin to pull actin filaments inwards?

• ATP
• Calcium
• Acetylcholine
• Sarcomere

What is the process of myosin pulling actin filaments over each other known as?

• Ratchet Mechanism
• Sliding Filament Theory
• Crossbridges
• Sarcoplasmic Reticulum

What pumps calcium back to the sarcoplasmic reticulum after a nerve impulse stops?

• ATP
• Calcium
• Acetylcholine
• Troponin

What causes the muscle to lengthen and relax after contraction?

• ATP stores
• Nerve impulse
• Calcium
• Actin returning to resting position