muscle contraction Flashcards
1
Q
actin structure
A
2
Q
myosin structure
A
3
Q
- stimulation
A
1) relaxed state
2) active potential arrives
- depolarises sacrolemma and sacroplasmic reticulum
- voltage gated calcium ion channels open
- calcium diffuses through sacroplasm
- binds to troponin - causes a conformational change
- pulls on tropomyosin - reveals actomyosin binding site
4
Q
- attachment
A
myosin head binds to am binding site by forming cross bridges
5
Q
attachment
A
myosin filament flexes
pulls actin along
releases adp
6
Q
detachment
A
atp binds to myosin head
detaches from actin - breaks cross bridges
7
Q
detachment
A
calcium activates ATPase on myosin head
- hydrolyses ATP
energy released returns myosin head to original position
binds to next am binding site
