Sliding Filament Theory Quiz

What is the result of muscle contraction when the load equals the muscle strength?

• The muscle lengthens

• The muscle shortens and moves the object

• The muscle remains the same length

• The muscle pushes the object

What causes the tropomyosin to lift and leave uncovered the binding sites on the actin?

• ATP attaches to myosin head

• Ca2+ binds to troponin

• Myosin head pivots

• ADP becomes ATP

What is the function of ATP in the myosin-actin interaction?

• Causes the myosin to shift

• Causes the myosin to detach from the actin

• Causes the myosin to bind to actin

• Causes the myosin to pivot

What is the analogy used to describe cross bridge formation?

• Running

• Cycling

• Swimming

• Rowing

What happens to the Z lines during a concentric contraction?

• They remain constant

• They disappear

• They move to the center of the sarcomere

• They get farther apart

What is the function of the myosin globular head during the power stroke?

• Binds to actin

• Pivots

• Pulls the actin past the myosin

• Detaches from the actin

What is the role of calcium ions in muscle contraction?

• They bind to myosin, enabling it to bind to actin

• They bind to troponin, causing a shift in tropomyosin

• They bind to ATP, providing energy for contraction

• They bind to actin, enabling it to bind to myosin

What happens to the sarcomere during muscle contraction?

• It lengthens

• It shortens

• It remains the same length

• It disappears

What is the role of ATP in the relaxation of a muscle?

• It binds to myosin, causing it to detach from actin

• It binds to actin, causing it to detach from myosin

• It binds to calcium ions, causing them to be pumped back into the sarcoplasmic reticulum

• It binds to troponin, causing tropomyosin to cover the binding sites on actin