Energetics, Metabolism, and Enzymes (Quiz 5)

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ∆G for the new reaction?

-20 kcal/mol

Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?

Catabolism

Which of the following is a statement of the first law of thermodynamics?

Energy cannot be created or destroyed.

Which of the following is true for all exergonic reactions?

The reaction proceeds with a net release of free energy.

Which of the following is (are) true for anabolic pathways?

They consume energy to build up polymers from monomers.

Which of the following is most similar in structure to ATP?

an RNA nucleotide

Which of the following types of reactions would decrease the entropy within a cell?

anabolic reactions

How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?

by changing the shape of the enzyme's active site

The active site of an enzyme is the region that

is involved in the catalytic reaction of the enzyme.

Protein kinases are enzymes that catalyze phosphorylation of target proteins at specific sites, whereas protein phosphatases catalyze removal of phosphate(s) from phosphorylated proteins. Phosphorylation and dephosphorylation can function as an on-off switch for a protein's activity, most likely through

the change in a protein's charge leading to a conformational change.