Some Enzymes Require Trace Metals to Function as Cofactors

Multiple Choice

Some enzymes require trace metals to function as cofactors. What do the trace metals do?

A) Trace metals are necessary for the transfer of uncharged chemical groups between substrates.
B) Trace metals provide energy for the reaction.
C) Trace metals must be present in the enzyme in order for the enzyme to bind substrate.
D) Trace metals are necessary for the transfer of electrons between substrates.
E) Trace metals covalently modulate the enzyme.