You eat a bowl of beans as part of your dinner. As you digest the beans, the proteins that are present get broken down to their component amino acids. As your body destroys the macromolecules that were present in the beans, is the energy present in those molecules destroyed? A. Yes. By breaking down these macromolecules, some of the energy they contained is destroyed. B. No. While the vast majority of the energy contained in these macromolecules is converted to heat, it is not actually destroyed. C. No. The energy contained within these macromolecules is converted into other forms of chemical energy and kinetic energy, though some is lost as heat. D. No. Breaking down molecules does not lead to the release of energy. 60. A particular chemical reaction is exergonic. What can you say about the relationship between the reactants and the products in this exergonic reaction? A. The reactants have more free energy than the products B. The reactants are likely more disordered and the products are likely more ordered C. The reactants cannot spontaneously react to generate the products D. The reactants likely have lower enthalpy than the products 40%
The Correct Answer and Explanation is:
Correct answers:
59. C. No. The energy contained within these macromolecules is converted into other forms of chemical energy and kinetic energy, though some is lost as heat.
60. A. The reactants have more free energy than the products.
Explanation:
Question 59:
When you eat a bowl of beans, the proteins are digested into amino acids. These amino acids can then be used in several ways: they may be used to build new proteins in your body, serve as substrates for metabolic processes, or be broken down further for energy. During digestion and metabolism, chemical bonds in these macromolecules are broken. These bonds store energy, and breaking them releases that energy. However, energy is not destroyed in this process. According to the First Law of Thermodynamics, energy cannot be created or destroyed but only transformed from one form to another.
In this case, some of the chemical energy is converted into usable forms, such as adenosine triphosphate (ATP), which powers various cellular processes. Some energy is also converted into kinetic energy or heat. The body cannot capture all the energy perfectly, so some is lost as heat. Still, this heat is not a destruction of energy but a transformation to a less usable form. Therefore, option C is correct, since it explains that the energy is transformed into different forms, including heat.
Question 60:
In an exergonic reaction, energy is released as the reaction proceeds. This happens because the free energy of the reactants is greater than that of the products. Free energy, often measured as Gibbs free energy (G), is the energy available to do work. If a reaction is exergonic, it has a negative change in free energy (∆G < 0), meaning that the reactants possess more free energy than the products.
This energy difference drives the reaction forward spontaneously. Therefore, option A is correct: in an exergonic reaction, the reactants have more free energy than the products. This makes the reaction thermodynamically favorable.
