In a skeletal muscle, what are the thin filaments primarily made of?

Thin filaments in skeletal muscle are primarily composed of actin, which is a globular protein that polymerizes to form long filaents. These actin filaments are crucial for muscle contraction, as they interact with thick filaments made of myosin. During contraction, the myosin heads attach to the actin filaments, pulling them inward and shortening the muscle fiber. This interaction is essential for the sliding filament model of muscle contraction, where the sliding of actin and myosin filaments past each other results in muscle shortening and force generation.

The other proteins mentioned have different roles: myosin is involved in forming the thick filaments, collagen provides structural support in connective tissues, and elastin gives elasticity to tissues, but none of these are components of the thin filaments.