9. Consider the following chemical reaction: X + Y → Z. In the diagram below, the dashed line represents the energetics of this reaction WITHOUT an enzyme. Which of the lines (a, b, c) in the diagram best represents the way the curve would look in the presence of an enzyme catalyst that increases the reaction rate?

Question

A. line (a)
B. line (b)
C. line (c)

Answer 1

The role of an enzyme is to lower the activation energy required for a reaction to proceed, allowing the reaction to occur more quickly. In a typical energy diagram, this is represented by a reduction in the height of the transition state (activation energy barrier) but does not change the overall energy difference between the reactants and products.

Looking at the options, the line that best represents the effect of an enzyme on the reaction would be one that shows a decrease in the activation energy (i.e., the peak height corresponding to the transition state) compared to the original dashed line but retains the same start and end energy levels for the reactants and products.

Without seeing the actual diagram, I cannot determine which line (a, b, or c) directly represents the presence of an enzyme. However, the correct answer will be one of the lines that shows a decrease in the activation energy peak while maintaining the same starting and ending energy levels as the original curve. You would want to look for a line that reflects this characteristic.