Yes, your phone will work; you do not need to worry. Pay-as-you-go mobiles are generally set to work abroad. However, if you do have a contract phone, then it is a vice to speak to your operator’s customer services and make sure you do tell them that you are going over to Turkey, so they can switch your phone to roaming if it is not done so.
You need to be aware of roaming charges as many people end up with huge bills by ignoring the fact that there are expensive additional charges for using your cell abroad. You will pay for receiving calls as well as making them. Roaming, in essential words, networks using each-others facilities to keep your communication channels open, end they bill each other for this.