Will upgrading my computers RAM make my game go faster? What else will it do?

I only have 1GB of RAM on my computer. I have one game on it, Half Life 2 the Orange Box, which usually runs pretty well. Sometimes it gets pretty choppy and the dialogue or sounds can repeat. Will upgrading to 2GB RAM help? I know upgrading video card (mines kind of crappy) would be best but my computer can't be upgraded for video card. So will more RAM help? If it does (or doesn't) what else would it do? Thanks.|||Yes they can but that depends from the CPU(microprocessor) speed too for games to run faster.