Never combine a worn pressure plate with a new clutch disc or vice versa. Always replace both the pressure plate and clutch disc with new components.
Throwout or release bearing is positioned in the center. When the clutch is pulled down, the contact of pressure plate and clutch disc gets interrupted from flywheel. And, the power is also interrupted and doesn’t flow from engine to the transmission until the clutch is not released. After releasing the clutch, the disc and pressure plate start working together and the clutch is engaged again to flow the power from engine to flywheel.