Final answer:
Enzymes act as catalysts in cells by reducing the activation energy required for chemical reactions, enabling them to occur more easily. The correct graphical representation would show the catalyzed reaction having a lower peak compared to the uncatalyzed reaction, indicating lower activation energy.
Step-by-step explanation:
In living cells, enzymes function as biological catalysts that aid in chemical reactions by reducing the activation energy required. This reduction in activation energy means that reactions can occur more easily and quickly than they would without the catalyst. When looking at energy diagrams, the uncatalyzed reaction (usually represented by a solid line) shows a higher peak — indicative of the higher activation energy needed for the reaction to proceed. The catalyzed reaction, on the other hand, is illustrated by a dotted or different line that reaches a lower peak, showing the decrease in activation energy provided by the enzyme.
The correct graph to illustrate these changes would show both reaction pathways beginning and ending at the same energy levels (because the enzyme does not change the initial or final energy states of the reactants or products), but the path of the catalyzed reaction would have a lower peak, representing the lower activation energy needed to reach the transition state and subsequently proceed to the final products.