Many co-enzymes are derivatives of which of the following?

What are the types of co-factors?

Assertion : $A$ co-enzyme or metal ion that is very tightly bound to enzyme protein is called a prosthetic group.
Reason : $A$ complete,catalytically active enzyme together with its bound prosthetic group is called an apoenzyme.

Organic compounds that are tightly bound to apoenzyme are known as:

Provide the full names of the following biological molecules:
$(1)$ $FAD$
$(2)$ $NAD$

What is the non-protein part associated with enzymes called?