Tropomyosin

Definition

Tropomyosin is a protein that wraps around actin filaments in muscle cells, playing a crucial role in regulating muscle contraction. It acts as a gatekeeper, blocking the binding sites for myosin on the actin molecules until calcium ions trigger contraction.

Related terms

Actin:

A globular protein that forms filaments which slide past myosin filaments to contract muscle fibers.

Myosin:

A motor protein that interacts with actin to cause muscle contraction by pulling on actin filaments.

Calcium ions: Play a key role in the contraction of muscles by binding to regulatory proteins that allow myosin to bind to actin