iPhone 4s power button flex cable, gold something

Hello, I have problem, when I was exchanging my iphone 4s power button I was watching by mistake on youtube exchange for iphone 4 not 4s. On Iphone 4 on flex cable is looks like gold "brick", and on Iphone 4s isn't but I have removed this from my iphone 4s I think how I can repair it, I rip it off. What do i need to replace it?? Is it do anything with my phone? And another question, under speaker on this flex cable is little square, this square cut out of this flex cable. Do i need to replace flex cable, or this wont do anything