Question

Whether or not an enzyme is active and present within a cell depends on all of the following EXCEPT

( ) if the gene for the enzyme has been turned on and the enzyme made.
( ) if the enzyme has been activated or inactivated by the addition of a phosphate group.
( ) whether an inhibitor is bound to the enzyme.
( ) whether the necessary cofactor is present.
( ) whether the enzyme catalyzes an endergonic or exergonic reaction.

Answer 1

Enzyme activity within a cell is influenced by gene expression, phosphorylation status, inhibitor presence, and cofactor availability but not by whether the enzyme catalyzes an endergonic or exergonic reaction.

Step-by-step explanation:

The activity and presence of an enzyme within a cell depend on various factors, but not whether the enzyme catalyzes an endergonic or exergonic reaction. Enzyme activity is influenced by whether the gene encoding the enzyme has been expressed, the enzyme's activation state is often related to the addition or removal of a phosphate group, the presence of an inhibitor, and the availability of necessary cofactors or coenzymes.

Cofactors may act as non-substrate molecules that bind competitively or allosterically at a site other than the active site. Activation may involve allosteric activators, which enhance enzyme function, while inhibition can occur competitively, noncompetitively, or allosterically. The primary control of enzyme regulation in the cellular metabolic pathway is known as feedback inhibition.