Question

1. the illustrations below show the reaction progress curves for two different reactions. indicate the activation energy as well as the $\delta g$ for each reaction. which reaction is endergonic? which reaction is exergonic? \\(\boldsymbol{\sqrt{}}_1\\)

Explanation:

Step1: Define activation energy

Activation energy ($E_a$) is the free energy difference between the substrate and the highest energy peak (transition state) on the curve.
For (A): $E_a = G_{\text{transition state (A)}} - G_{\text{substrate (A)}}$
For (B): $E_a = G_{\text{transition state (B)}} - G_{\text{substrate (B)}}$

Step2: Define $\Delta G$ (free energy change)

$\Delta G = G_{\text{product}} - G_{\text{substrate}}$
For (A): $\Delta G = G_{\text{product (A)}} - G_{\text{substrate (A)}} < 0$ (product has lower free energy)
For (B): $\Delta G = G_{\text{product (B)}} - G_{\text{substrate (B)}} > 0$ (product has higher free energy)

Step3: Classify reaction type

Exergonic reactions have $\Delta G < 0$; endergonic reactions have $\Delta G > 0$.

Answer:

1. Activation Energy:

• For Reaction (A): Activation energy is the vertical difference between the substrate free energy and the highest free energy peak on curve (A).
• For Reaction (B): Activation energy is the vertical difference between the substrate free energy and the highest free energy peak on curve (B).

1. $\Delta G$:

• Reaction (A): $\Delta G = G_{\text{product}} - G_{\text{substrate}} < 0$ (negative value)
• Reaction (B): $\Delta G = G_{\text{product}} - G_{\text{substrate}} > 0$ (positive value)

1. Reaction Classification:

• Reaction (A) is exergonic.
• Reaction (B) is endergonic.