How does killing of predators affect the food chain?

Predators help maintain the food chain, without them animals such as deer would overpopulate and would not be able to be maintained with just hunting season. So killing off a predator would be killing off a huge part in that ecosystems food chain and it would eventually overpopulate, especially it say it were a pack of wolves, since their territory extends so far and they have to keep that part of the ecosystem under control.