Across
- 2. the space in which actin and myosin filaments overlap
- 4. A protein that wraps around the actin filament, covering the binding sites for myosin in a relaxed muscle.
- 6. these attach to actin filaments and create the border of the sarcomere
- 8. A thin filamentous protein found in muscle cells that forms the backbone of the thin filaments.
- 10. A protein complex found on the thin filament that binds to calcium ions and regulates the interaction between actin and myosin.
- 12. A thick filamentous protein found in muscle cells that contains the myosin heads responsible for crossbridge formation.
- 13. The attachment of the myosin heads to the exposed binding sites on actin, forming crossbridges between the thin and thick filaments.
Down
- 1. The return of the muscle to its resting state after contraction, involving the cessation of calcium ion release, reuptake of calcium into the sarcoplasmic reticulum, and the blocking of the binding sites on actin by tropomyosin.
- 3. The molecule that provides the energy needed for muscle contraction. ATP is hydrolyzed to ADP (Adenosine diphosphate) and inorganic phosphate (Pi), releasing energy that powers the crossbridge cycling.
- 5. area between actin filaments where there is only myosin
- 7. The repetitive process of myosin heads binding to actin, performing a power stroke (resulting in filament sliding), detaching, and resetting for the next binding event, fueled by the hydrolysis of ATP.
- 9. ions Play a crucial role in muscle contraction by binding to troponin and triggering the movement of tropomyosin, exposing the binding sites on actin.
- 11. area where only actin filaments are