As the distance from Z line to Z line decreases, which bands shorten in a sarcomere?

1. the I band and H band 2. the I band and A band
3. the A band and H band 4. all bands shorten
Subtopic:  Sliding Filament Theory |
 88%
From NCERT
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What protein is arranged along the length of actin filaments and is involved in regulation of skeletal muscle contraction?

1. Troponin 2. Calmodulin
3. Tropomyosin 4. Light meromyosin
Subtopic:  Sliding Filament Theory |
 64%
From NCERT
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During relaxation of a skeletal muscle:

1. Calcium ions that are bound to troponin C now bind to troponin A
2. Cross bridge formation between myosin head and actin takes place
3. The A band of the sarcomere lengthens
4. Calcium ions are pumped back to the sarcoplasmic cisternae
Subtopic:  Sliding Filament Theory | Energy for Muscle Contraction |
 84%
From NCERT
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During muscle contraction, when the myosin head releases ADP and iP it:
1. forms cross bridge with actin
2. pulls actin towards M-line
3. goes back to its relaxed state
4. gets detached from the cross bridge

Subtopic:  Sliding Filament Theory | Energy for Muscle Contraction |
From NCERT
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Which of the following masks the active sites on actin when a skeletal muscle is relaxed?

1. Tropomyosin 2. Troponin
3. Calmodulin 4. Ubiquitin
Subtopic:  Sliding Filament Theory | Energy for Muscle Contraction |
 86%
From NCERT
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During muscle contraction, the event shown in the following diagram describes:

 

1. cross bridge detachment
2. the power stroke or working stroke
3. cross bridge formation
4. cocking of myosin head

Subtopic:  Sliding Filament Theory |
 76%
From NCERT
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Cross bridge formation during muscle contraction involves:

1. troponin and actin 2. tropomyosin and myosin
3. myosin and troponin 4. myosin and actin
Subtopic:  Sliding Filament Theory |
 72%
From NCERT
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