Which are composed of actin?

A) all myofilaments
B) thin filaments
C) thick filaments
D) none of the above

Actin

A globular protein that forms microfilaments, playing a key role in muscle contraction and cell movement.

Myofilaments

Protein filaments consisting primarily of actin and myosin that function in the contraction and relaxation of muscle cells.

Thin Filaments

Protein fibers in muscle cells that work with thick filaments to cause muscle contraction.