1) What does it mean for a system to be in a higher level of entropy? How can it
ID: 282736 • Letter: 1
Question
1) What does it mean for a system to be in a higher level of entropy? How can it be reduced?
a) Higher level of entropy refers to higher state of disorder in the system and it can be reduced by input of energy to lower the entropy.
b) Higher level of entropy refers to higher state of symmetry in the system and it can be reduced by release of energy to lower the entropy.
c) Higher level of entropy refers to low disorder in the system and it can be reduced by input of energy to increase the entropy.
d) Higher level of entropy refers to higher state of disorder in the system and it can be reduced by providing a catalyst to lower the entropy.
2) Energy transfers take place constantly in every day activities. Think of two scenarios: cooking on a stove and driving. Explain how the second law of thermodynamics applies to these scenarios.
a) Heat is lost into the room while cooking and into the metal of the engine during gasoline combustion.
b) Heat gained while cooking helps to make the food and heat released due to gasoline combustion helps the car accelerate.
c) The energy given to the system remains constant during cooking and more energy is added to the car engine when the gasoline combusts.
d) The energy given to the system for cooking helps to make food and energy in the car engine remains conserved when gasoline combustion takes place.
3) Explain why the lock-and-key model does not adequately represent the relationship between hexokinase and glucose.
a) Hexokinase changes conformation in presence of glucose
b) Hexokinase induces change in the glucose structure
c) Hexokinase requires an effector molecule to bind at allosteric site
d) Hexokinase binds glucose without any conformational change
4) How is the high amount of energy that can be released by ATP breakdown, and the ultimate energy release, expressed with a chemical symbol?
a) EA does not show any correlation with ATP hydrolysis.
b) It is expressed by an elevated EA for ATP hydrolysis.
c) It is expressed by a negative EA for ATP hydrolysis.
d) It is expressed by an intermediate EA for ATP hydrolysis,
Explanation / Answer
1. a) Higher level of entropy refers to higher state of disorder in the system and it can be reduced by input of energy to lower the entropy.
In accordance with the second law of thermodynamics, higher is the entropy (degree of randomness), lower be the energy of the system and hence higher will be its stability. If energy is provided to the system, system becomes less stable due to decrease in entropy.
2. a) Heat is lost into the room while cooking and into the metal of the engine during gasoline combustion.
Not all of the heat goes to cooking the food instead some of it is lost as heat energy to the surrounding air, increasing entropy. Also in case of gasoline combustion, metal absorbs heat resulting in increase in entropy.
3. a) Hexokinase changes conformation in presence of glucose.
Change in conformation results in additional interaction between glucose and hexokinase. This is an example of induced-fit model.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.