WHy is my car making a groaning sound when I make sharp turns?

Sounds like you could be low on power steering fluid. There could be other power steering related issues as well. I recommend you have the system inspected, especially to check for leaks if you have lost fluid.

u turns and sharp aggressive turns put maximum load on wheel bearings and suspension components.more than likely wheel bearings! ( if clicking noise then examine the cv axels shaft joints)

you need to change the oil in your rear differential, go in an empty parking, at low speed, turn your steering to the max while turning,if it's noisy you need to change oil, the oil must be change each 30 000 km, about 300$