View the animation below, then complete the quiz to test your knowledge of the concept.
|
| 1 | An action potential causes calcium ions to diffuse from the ________ into the ________. |
 | A) | sarcoplasmic reticulum ; sarcolemma |
| B) | sarcoplasmic reticulum ; sarcoplasm |
| C) | sarcoplasm ; sarcoplasmic reticulum |
| D) | sarcoplasm ; sarcolemma |
| E) | sarcolemma ; sarcoplasm |
|
| 2 | Which of the following best describes the role of Ca2+ in muscle contraction? |
| A) | It binds to tropomyosin, moving troponin, so that myosin heads can bind to actin. |
| B) | It binds to tropomyosin, moving troponin, so that actin heads can bind to myosin. |
| C) | It binds to troponin, moving tropomyosin, so that myosin heads can bind to actin. |
| D) | It binds to troponin, moving tropomyosin, so that actin heads can bind to myosin. |
| E) | It binds to actin, moving myosin, so that troponin can bind to tropomyosin. |
|
| 3 | All of the following are filamentous proteins EXCEPT |
| A) | actin. |
| B) | myosin. |
| C) | troponin. |
| D) | tropomyosin. |
| E) | troponin and tropomyosin. |
|
| 4 | An action potential causes depolarization of the T tubule membrane. |
| A) | True |
| B) | False |
|
| 5 | T-tubules are invaginations of the sarcolemma of a muscle cell. |
| A) | True |
| B) | False |