Psp memory?

May be...

if i had a 1 gb memory card for psp and i played a game medal of honors heros 2 would that take up the whole card?

there is no way it would, the thing that takes up most of ur memory card is movies and music, i had a ps2 which can only play games and nothing else and i had an 8mb memory card for all of my games

I very much doubt it.

nooo way onless there was a tiny bit of memory left or if you made lots and lots of save files

Certainly not, most of PSP games require low amount of free memory.