Assertion: muscle fiber's myofibril | /r/HasProperty | long protein cords
Facets:
Source sentences:
text: Most of the sarcoplasm is filled with myofibrils, which are long protein cords composed of myofilaments.
text: The myofibrils are long protein bundles
text: Most of the sarcoplasm is filled with myofibrils, which are long protein cords composed of myofilaments.