Which term most precisely describes the cellular process of breaking down large molecules into smaller ones? A) catalysis B) metabolism C) anabolism D) dehydration E) catabolism
E
Which of the following is (are) true for anabolic pathways? A) They do not depend on enzymes. B) They are usually highly spontaneous chemical reactions. C) They consume energy to build up polymers from monomers. D) They release energy as they degrade polymers to monomers
C
Which of the following is a statement of the first law of thermodynamics? A) Energy cannot be created or destroyed. B) The entropy of the universe is decreasing. C) The entropy of the universe is constant. D) Kinetic energy is stored energy that results from the specific arrangement of matter. E) Energy cannot be transferred or transformed.
A
For living organisms, which of the following is an important consequence of the first law of thermodynamics? A) The energy content of an organism is constant. B) The organism ultimately must obtain all of the necessary energy for life from its environment. C) The entropy of an organism decreases with time as the organism grows in complexity. D) Organisms are unable to transform energy. E) Life does not obey the first law of thermodynamics.
B
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate tothe second law of thermodynamics? A) Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time. B) Life obeys the second law of thermodynamics because the decrease in entropy as the organism growsis balanced by an increase in the entropy of the universe. C) Living organisms do not follow the laws of thermodynamics. D) As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth. E) Living organisms are able to transform energy into entropy.
D
Whenever energy is transformed, there is always an increase in the A) free energy of the system. B) freeenergy of the universe. C) entropy of the system. D) entropy of the universe. E) enthalpy of the universe.
D
Which of the following statements is a logical consequence of the second law of thermodynamics? A) If the entropy of a system increases, there must be a corresponding decrease in the entropy of the universe. B) If there is an increase in the energy of a system, there must be a corresponding decrease in the energy of the rest of the universe. C) Every energy transfer requires activation energy from the environment. D) Every chemical reaction must increase the total entropy of the universe. E) Energy can be transferred or transformed, but it cannot be created or destroyed.
D
Which of the following statements is representative of the second law of thermodynamics? A) Conversion of energy from one form to another is always accompanied by some gain of free energy. B) Heat represents a form of energy that can be used by most organisms to do work. C) Without an input of energy, organisms would tend toward decreasing entropy. D) Cells require a constant input of energy to maintain their high level of organization. E) Every energy transformation by a cell decreases the entropy of the universe.
D
Which of the following types of reactions would decrease the entropy within a cell? A) dehydration reactions B) hydrolysis C) respiration D) digestion E) catabolism
A
The organization of organisms has become increasingly complex with time. This statement A) is consistent with the second law of thermodynamics. B) requires that due to evolution, the entropy of the universe increased. C) is based on the fact that organisms function as closed systems. D) A and B only E) A, B, and C
A
Which of the following is an example of potential rather than kinetic energy? A) a boy mowing grass B) water rushing over Niagara Falls C) a firefly using light flashes to attract a mate D) a food molecule made up of energy-rich macromolecules E) an insect foraging for food
D
Which of the following is considered an open system? A) an organism B) liquid in a corked bottle C) a sealed terrarium D) food cooking in a pressure cooker
A
Which of the following is true of metabolism in its entirety? A) Metabolism depends on a constant supply of energy from food B) Metabolism depends on an organism's adequate hydration C) Metabolism utilizes all of an organism's resources D) Metabolism is a property of organismal life E) Metabolism manages the increase of entropy in an organism
D
Which of the following is true for all exergonic reactions? A) The products have more total energy than the reactants. B) The reaction proceeds with a net release of free energy. C) Some reactants will be converted to products. D) A net input of energy from the surroundings is required for the reactions to proceed. E) The reactions are nonspontaneous.
B
Chemical equilibrium is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell? A) a reaction in which the free energy at equilibrium is higher than the energy content at any point away from equilibrium B) a chemical reaction in which the entropy change in the reaction is just balanced by an opposite entropy change in the cell's surroundings C) an endergonic reaction in an active metabolic pathway where the energy for that reaction is supplied only by heat from the environment D) a chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive E) There is no possibility of having chemical equilibrium in any living cell.
D
A chemical reaction that has a positive (+)
endergonic
Which of the following best describes enthalpy (H)? A) the total kinetic energy of a system B) the heat content of a chemical system C) the system's entropy D) the cell's energy equilibrium E) the condition of a cell that is not able to react
B
Why is ATP an important molecule in metabolism? A) Its hydrolysis provides an input of free energy for exergonic reactions. B) It provides energy coupling between exergonic and endergonic reactions. C) Its terminal phosphate group contains a strong covalent bond that when hydrolyzed releases free energy. D) Its terminal phosphate bond has higher energy than the other two. E) A, B, C, and D
B
When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP. Which of the following is the best explanation for this observation? A) Cells are open systems, but a test tube is a closed system. B) Cells are less efficient at heat production than nonliving systems. C) The hydrolysis of ATP in a cell produces different chemical products than does the reaction in a test tube. D) The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube does not need enzymes. E) Reactant and product concentrations are not the same
E
Which of the following is most similar in structure to ATP? A) an anabolic steroid B) a DNA helix C) an RNA nucleotide D) an amino acid with three phosphate groups attached E) a phospholipid
C
What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways? A) feedback regulation B) bioenergetics C) energy coupling D) entropy E) cooperativity
C
Which of the following statements is true concerning catabolic pathways? A) They combine molecules into more energy-rich molecules. B) They are usually coupled with anabolic pathways to which they supply energy in the form of ATP. C) They are endergonic. D) They are spontaneous and do not need enzyme catalysis. E) They build up complex molecules such as protein from simpler compounds.
B
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? A) It is used to power yet more cellular work. B) It is used to store energy as more ATP. C) It is used to generate ADP from nucleotide precursors. D) It is lost to the environment. E) It is transported to specific organs such as the brain.
D
When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell? A) It is released as an excretory waste. B) It can only be used to regenerate more ATP. C) It can be added to water and excreted as a liquid. D) It can be added to other molecules in order to activate them. E) Itcan enter the nucleus to affect gene expression.
D
What must be the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in DNA and RNA? A) The sugar molecule is different. B) The nitrogen-containing base is different. C) The number of phosphates is three instead of one. D) The number of phosphates is three instead of two. E) There is no difference
E
Which of the following statements is (are) true about enzyme-catalyzed reactions? A) The reaction is faster than the same reaction in the absence of the enzyme. B) The free energy change of the reaction is opposite from the reaction in the absence of the enzyme. C) The reaction always goes in the direction toward chemical equilibrium. D) A and B only E) A, B, and C
A