To take risks is a general description. For example:
He likes to take risks so he is climbing the mountain without a harness.
He called his boss an idiot. He likes to take risks.
I probably don't have time but I'm going to take a risk and go to the bathroom.
To risk requires an object; you need to risk something. For example:
He is risking his life by climbing the mountain without a harness.
He risked his job by calling his boss an idiot.
I probably don't have time to go to the bathroom but I am going to risk it.