How Stop Update function of other scene

Hello
I have a game that have 2 scenes and at each one of them unity3d editor profiler window show other scene update functions working and waste CPU how could I stop them from this scene?
Should I use disable/enable scripts on loading levels and how shall I do it?
thanks in advance

You can check right in the first line in your Update() method:

Application.LoadedLevel

private void Update()
{
      if (Application.LoadedLevel == SOME_INDEX) return;
      // some of your other code here
}

This code will skip rest of your Update code if SOME_INDEX matches scene index you want to skip update in