So as soon as calcium binds to our troponin, the troponin basically changes its shape. It experiences a conformational change. And as it changes its shape, it causes our trophymycin to also change its shape and shift. And as our trophymycin, shown in blue, actually shifts, it exposes special binding sites on the actin filament known as our myosin binding site. So this is basically where our myosin heads found on the thick filament, actually bind to our thin filament. So this green region, which was blocked on this diagram is exposed as soon as our calcium binds onto our troponin.