movement and exercise
Study online at https://quizlet.com/_bbto47
1. actin thin filaments with two strands twisted around each other
2. myosin thick filaments with bulbous heads which project to the
side
3. myofibril tightly packed filament bundles found within skeletal mus-
cle fibers
4. tropomyosin fibrous strand around actin filament
5. troponin globular protein involved in muscle contraction
6. A band whole myosin filament length, included overlap of actin
and myosin
7. I band actin only
8. Z line where actin filaments connect
9. sarcomere z line to z line
10. H line myosin only
11. sliding filament 1. action potential travels to neuromuscular junction caus-
theory process ing Ca2+ ions to be released from sarcoplasmic reticulum
2. Ca2+ binds to troponin causing troponin to changed
shape causing tropomyosin to move out of the actin
myosin binding site
3. myosin bulbous head now attaches to actin myosin
binding site forming a cross bridge
4. ATP breaks down releasing energy allowing myosin
filament head to pull actin inwards shortening the muscle
fibres
5. this occurs down whole length of muscle
6. ATP breaks down again so myosin detaches from actin
breaking the cross bridge
7. as the actin has moved along a new binding site is
aligned with the myosin
8. the process can now repeat while there are still Ca2+
ions and ATP molecules available
1/3
Study online at https://quizlet.com/_bbto47
1. actin thin filaments with two strands twisted around each other
2. myosin thick filaments with bulbous heads which project to the
side
3. myofibril tightly packed filament bundles found within skeletal mus-
cle fibers
4. tropomyosin fibrous strand around actin filament
5. troponin globular protein involved in muscle contraction
6. A band whole myosin filament length, included overlap of actin
and myosin
7. I band actin only
8. Z line where actin filaments connect
9. sarcomere z line to z line
10. H line myosin only
11. sliding filament 1. action potential travels to neuromuscular junction caus-
theory process ing Ca2+ ions to be released from sarcoplasmic reticulum
2. Ca2+ binds to troponin causing troponin to changed
shape causing tropomyosin to move out of the actin
myosin binding site
3. myosin bulbous head now attaches to actin myosin
binding site forming a cross bridge
4. ATP breaks down releasing energy allowing myosin
filament head to pull actin inwards shortening the muscle
fibres
5. this occurs down whole length of muscle
6. ATP breaks down again so myosin detaches from actin
breaking the cross bridge
7. as the actin has moved along a new binding site is
aligned with the myosin
8. the process can now repeat while there are still Ca2+
ions and ATP molecules available
1/3
