iMac and MacBook Pro Memory Specifications
According to Apple's support page the Mid 2009 MBP has 1066 MHz DDR3 Ram while the Early 2011 iMac has 1333 Mhz DDR3 Ram. The Pin number is the same.

According to this thread in the Macrumors forum 1333 DDR3 Ram can be installed on the MBP with DDR3 Ram, but would only be clocked at 1066 MHz.