Here a definition of kamma (more can be found here):
kamma：（Sanskrit：karma）：'action'，correctly speaking denotes the wholesome and unwholesome volitions （kusala- and akusala-cetanā） and their concomitant mental factors，causing rebirth and shaping the destiny of beings．These kammical volitions （kamma cetanā） become manifest as wholesome or unwholesome actions by body （kāya-kamma），speech （vacī-kamma） and mind （mano-kamma）．Thus the Buddhist term 'kamma' by no means signifies the result of actions，and quite certainly not the fate of man，or perhaps even of whole nations （the so-called wholesale or mass-kamma），misconceptions which，through the influence of theosophy，have become widely spread in the West．
As you can see, kamma is not an energy or holds memory. Nor does it go from body to body. When you intentional speak, this action is kamma. When you intentional give something to someone, that act is kamma. When you think intentionally, this is kamma.
The body is the body, the mind is the mind. Those two are different things. They interact with each other, but they don't mix.
You might also want to check out further resources mentioned here.