actin
n. uncountable C2 Proficiency US //ˈæktən// UK //ˈæktɪn// actin
n. a protein found in your muscles that helps them move. It works with another protein to make muscles tighten and relax.
n. a globular protein that forms microfilaments in eukaryotic cells and plays a critical role in muscle contraction and cell motility.
Actin is essential for muscle movement.
When you lift a heavy object, actin and myosin filaments slide past each other to contract your muscles.
The dynamic assembly and disassembly of actin filaments provide the mechanical force necessary for cell crawling and the maintenance of structural integrity within the cytoskeleton.
Usage
Uncountable in its general biological sense; countable when referring to specific isoforms or types of the protein.