2_Chapter 8 Practice Test Flashcards
Which of the following correctly states the relationship between anabolic and catabolic pathways?
A The flow of energy between catabolic and anabolic pathways is reversible.
B Energy derived from catabolic pathways is used to drive the breakdown of organic molecules in anabolic pathways.
C Catabolic pathways produce usable cellular energy by synthesizing more complex organic molecules.
D Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.
E Degradation of organic molecules by anabolic pathways provides the energy to drive catabolic pathways.
D Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.
The synthesis of complex molecules in anabolic pathways requires an input of energy from catabolic pathways.
Organisms are described as thermodynamically open systems. Which of the following statements is consistent with this description?
A Organisms acquire energy from, and lose energy to, their surroundings.
B Because energy must be conserved, organisms constantly recycle energy and thus need no input of energy.
C The metabolism of an organism is isolated from its surroundings.
D Heat produced by the organism is conserved in the organism and not lost to the environment.
E All of the listed responses are correct.
A Organisms acquire energy from, and lose energy to, their surroundings.
Open systems are those in which energy and materials can be exchanged between the system and its surroundings.
Consider the growth of a farmer’s crop over a season. Which of the following correctly states a limitation imposed by the first or second law of thermodynamics?
A Growth of the crops must occur spontaneously.
B The process of photosynthesis produces energy that the plant uses to grow.
C The entropy of the universe must decrease to account for the increased entropy associated with plant growth.
D To obey the first law, the crops must represent an open system.
E All of the listed responses are correct.
D To obey the first law, the crops must represent an open system.
The first law states that energy cannot be created. The growth of plants stores much energy in the body of the plant. That energy must have been obtained from the plant’s environment; thus the plant must be an open system.
Which of the following states the relevance of the first law of thermodynamics to biology?
A Energy can be freely transformed among different forms as long as the total energy is conserved.
B Energy is destroyed as glucose is broken down during cellular respiration
C Photosynthetic organisms produce energy in sugars from sunlight.
D Living organisms must increase the entropy of their surroundings.
E Because living things consume energy, the total energy of the universe is constantly decreasing.
A Energy can be freely transformed among different forms as long as the total energy is conserved.
The first law of thermodynamics states energy can be transformed, but can neither be created nor destroyed.
Which of the following reactions would be endergonic?
A ATP → ADP + Pi
B HCl → H+ + Cl-
C glucose + fructose → sucrose
D C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
E All of the listed responses are correct.
C glucose + fructose → sucrose
In this case the product is more complex (lower entropy) than the reactants, and like many anabolic reactions, this one requires the input of energy.
An exergonic (spontaneous) reaction is a chemical reaction that __________.
A cannot occur outside of a living cell
B releases energy when proceeding in the forward direction
C is common in anabolic pathways
D occurs only when an enzyme or other catalyst is present
E leads to a decrease in the entropy of the universe
B releases energy when proceeding in the forward direction
Exergonic reactions proceed with a net release of free energy and they occur spontaneously.
