No, you can not upgrade the video in a MacBook. There is no "card", the GPU (an Intel chip with no dedicated Video RAM) is soldered on the the motherboard. This is normal for a laptop.
You can upgrade the RAM in a MacBook, but this is unlikely to benefit graphics performance. The GPU uses the system RAM, and as far as I know there is no way of forcing how much of the system RAM is used as graphics RAM, OS X makes those decisions for you.
If you do upgrade system RAM, make sure you get full-speed (667MHz DDR2 SDRAM (PC2-5300)) sticks in a matched pair (the MacBook has two RAM slots, and for maximum memory bandwidth, both slots should contain the same amount of RAM). Upgrading (unless you do a BTO at the Apple store) will involve removing the RAM you've already got, which you can sell.
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You can upgrade the RAM in a MacBook, but this is unlikely to benefit graphics performance. The GPU uses the system RAM, and as far as I know there is no way of forcing how much of the system RAM is used as graphics RAM, OS X makes those decisions for you.
If you do upgrade system RAM, make sure you get full-speed (667MHz DDR2 SDRAM (PC2-5300)) sticks in a matched pair (the MacBook has two RAM slots, and for maximum memory bandwidth, both slots should contain the same amount of RAM). Upgrading (unless you do a BTO at the Apple store) will involve removing the RAM you've already got, which you can sell.