206 Chapter 9 (^)
(^) Action potential (^)
Sarcolemma^ T tubule^
(^) Sarcoplasmic (^)
reticulum (^)
(^) Myofibril (^)
Ca++^
Calcium attaches
Troponin (^)
Troponin^ to troponin^ active sitemoves off^
(^) Actin (^)
Tropomyosin ADP (^)
+P^
(^) Myosin (^)
Step 1:
ADP
Active site +P^
Cross-^
bridge
Step 2: Step 3:ATP
Step 4: Step 5:ADP
+P
ADP
+P
(^) ®
Learning
Cengage ©
Figure 9- 4 The interaction of the activated myosin cross-bridges with the actin filaments pulling the actin in
among the myosin, resulting in contraction.