Which statement is false regarding enzymatic reactions?

The statement that enzymes can alter ΔG is false. Enzymes serve as catalysts in biochemical reactions, meaning they speed up the rate at which reactions occur by lowering the activation energy required for the reaction to proceed. However, they do not change the overall free energy change (ΔG) of the reaction itself. The ΔG reflects the difference in energy between the reactants and products and indicates whether a reaction is spontaneous or requires energy input.

Enzymes operate by providing an alternative pathway for the reaction but do not influence the intrinsic energetics of the reaction; thus, the value of ΔG remains constant regardless of the presence of enzymes. This is a fundamental principle of enzyme kinetics and thermodynamics in biochemical processes. The other statements are true: enzymes are indeed essential for many (though not all) biochemical pathways, they can facilitate reactions that occur spontaneously without the input of external energy (as indicated by a negative ΔG), and they significantly increase the rate of reactions.