Muscle contraction

In what part of our muscle structure does the sliding filament theory (muscle contraction) occur in?

• fascicles

• muscle fibers

• sarcomeres

• epimysium

What ion begins muscle activation?

• sodium (Na+)

• potassium (K+)

• Oxygen (O-)

• Calcium (Ca2+)

How does calcium initiate muscle contraction?

• Calcium attaches to actin, allowing cross bridges to form

• Calcium causes myosin to attach to the actin protein

• Calcium causes ATP to move to myosin heads

• Calcium turns the electrical signal into a chemical signal

What molecule attaches to the myosin head?

• ATP

• ADP

• P (phosphorous)

• Ca2+

When ATP attaches to the myosin head it is hydrolyzed. What is the result of this reaction?

• ADP and Ca2+ form

• ATP and ADP form

• ADP and P form

• P and Ca2+ form

When ADP and P leave the myosin head, what action occurs?

• The cross bridge is formed

• The myosin head pulls the actin forward

• The myosin head is released

• The actin unwinds

What molecule causes the myosin head to detach from actin?

• ATP

• ADP

• Ca2+

• P

To which structure does a sarcomere contract to?

• Z line

• M line

• I band

• A band