Actin and Myosin

When a muscle is in a contracted position, what is the relationship between actin filaments?

• They are on top of one another

• They are beside each other

• They are close to each other

• They are far apart from each other

When a muscle is relaxed and in a lengthened position, what is the relationship between actin filaments?

• They are on top of one another

• They are beside each other

• They are close to each other

• They are far apart from each other

What is the name of structure #1?

• Troponin

• Tropomyosin

• Actin

• ATP

A calcium deficiency would

• create uncoordinated muscle contractions

• allow muscle contraction, but not relaxation

• prevent contraction by preventing myosin from binding to actin

• have no effect on contraction

binds to myosin head causing myosin to release actin.

• ATP

• ADP

• Actin

• Calcium

___are thin filaments.

• troponin

• tropomyosin

• actin

• myosin

___are thick filaments.

• actin

• myosin

• troponin

• tropomyosin

What is our current model of muscle contraction called?

• Fluid Mosaic Model

• Sliding Filament Theory

• Newton's Laws of Motion

• Big Bang Theory

Which of the following statements correctly explains the sliding filament model?

• Actin head attaches to a binding site on a myosin filament, forming a cross bridge.

• Myosin head attaches to a binding site on an actin filament, forming a neuromuscular junction.

• Actin head attaches to a binding site on a myosin filament, forming a neuromuscular junction.

• Myosin head attaches to a binding site on an actin filament, forming a cross bridge.

Myofibrils are made up of two types of proteins known as?

• Actin and Myosin

• Troponin and Tropomyosin

• Myoglobin and hemoglobin

• none of these