Assertion: muscle fiber's myofibril | /r/HasProperty | myofilament
Facets:
Source sentences:
text: Most of the sarcoplasm is filled with myofibrils, which are long protein cords composed of myofilaments.
text: Each myofibril is composed of many myofilaments that are the actual contractile actin and myosin proteins.
text: Most of the sarcoplasm is filled with myofibrils, which are long protein cords composed of myofilaments.