Powerbook function keys

As you may or may not have heard, I acquired a new powerbook today. Now, my question is this: the function keys across the top default so that you have to press FN plus the key you want in order to access that shortcut. They do this because the function keys also control different things such as screen brightness, keyboard backlight brightness. Is there any way to switch it so that i don’t have to press fn to use the function keys, so that i have to press fn to access the screen brightness and what not? does that make any sense?