How to use an Arduino to turn a supply voltage to another device on and off?
As @dandavis said, a MOSFET as a switch would be the easiest solution. In your case, go for the P-Channel mosfet (explained in the guide under P-channel MOSFET Switch). That way you can get output 0 Volt with arduino pin HIGH and a 5V output when pin is LOW. Since MOSFET would be voltage driven you do not need to worry. If you have further questions check this guide.