Cross Bridge Cycle Control

Question 1

1st step?

Answer 1

Action potential is carried to the sarcoplasmic reticulum

Question 2

2nd step?

Answer 2

Ca2+ ions are released from the sarcoplasmic reticulum into the sarcoplasm

Question 3

3rd step?

Answer 3

Ca2+ ions bind to troponin, which is attached to tropomyosin. Troponin changes shape, tropomyosin moves aside to expose the actin binding sites for the myosin heads

Question 4

4th step?

Answer 4

While Ca2+ is bound and ATP is available, cross bridge cycle occurs

Question 5

5th step?

Answer 5

Action potential stops, Ca2+ is actively transported into the sarcoplasmic reticulum which causes Ca2+ to detach from troponin and tropomyosin to move back