| Type of Protein |
Thin filamentous protein |
Thick filamentous protein |
| Structure |
Helical filaments formed by G-actin |
Molecules with elongated tail and globular head regions |
| Function in Muscle Contraction |
Provides attachment sites for myosin |
Generates force and interacts with actin during muscle contraction |
| Arrangement in Sarcomeres |
Forms thin filaments within sarcomeres |
Arranged between actin filaments in sarcomeres |
| Role in Sliding Filament Theory |
Participates in the sliding of actin filaments past myosin filaments |
Undergoes conformational changes to generate force and propel actin |
| Cellular Functions |
Component of the cytoskeleton, involved in cell motility, cytokinesis, and intracellular transport |
Primarily associated with muscle contraction but also present in non-muscle cells for various cellular processes |
| Location |
Present in eukaryotic cells, especially muscle cells |
Present in eukaryotic cells, primarily muscle cells, but also found in other cell types |
| Interaction |
Binds to myosin heads during muscle contraction |
Binds to actin and undergoes a series of conformational changes during muscle contraction |
