If you were to expose glucose to oxygen on your lab bench, why would you not expect to see it burn as described by the reaction in Figure 8.6? a. The reaction is endergonic and requires an input of energy.b.The reaction is not spontaneous unless an enzyme is added.c. The sugar must first be phosphorylated to increase its potential energy.d. Activation energy is required for the sugar and oxygen to reach their transition state.

Verified step by step guidance

1. Step 1: Understand the reaction depicted in Figure 8.6, which shows the oxidation of glucose (C6H12O6) in the presence of oxygen (O2) to produce carbon dioxide (CO2), water (H2O), and energy.
2. Step 2: Recognize that the reaction involves redox processes where glucose is oxidized and oxygen is reduced, leading to a decrease in potential energy and release of energy.
3. Step 3: Identify the key factors that prevent glucose from spontaneously burning on the lab bench, such as the need for activation energy to initiate the reaction.
4. Step 4: Consider the options provided: (a) endergonic reaction requiring energy input, (b) non-spontaneous reaction without an enzyme, (c) need for phosphorylation of sugar, and (d) requirement of activation energy for the transition state.
5. Step 5: Analyze the options and determine that the correct answer is related to the requirement of activation energy for the reaction to proceed, as indicated by the need for an initial energy input to reach the transition state.

Key Concepts

Endergonic vs. Exergonic Reactions

Endergonic reactions require an input of energy to proceed, while exergonic reactions release energy. In the context of glucose oxidation, the reaction is exergonic, meaning it releases energy, but it does not spontaneously ignite without sufficient activation energy. Understanding this distinction is crucial for explaining why glucose does not burn immediately upon exposure to oxygen.

Activation Energy

Activation energy is the minimum energy required for a chemical reaction to occur. Even for exergonic reactions like the combustion of glucose, a certain amount of energy must be supplied to reach the transition state before the reaction can proceed. This concept helps explain why glucose does not spontaneously combust in the presence of oxygen at room temperature.

Redox Reactions

Redox reactions involve the transfer of electrons between substances, where one substance is oxidized (loses electrons) and another is reduced (gains electrons). In the reaction between glucose and oxygen, glucose is oxidized to carbon dioxide, while oxygen is reduced to water. Understanding redox processes is essential for grasping the underlying chemistry of glucose metabolism and its energy release.