Lesson 5 Ground Rules of Metabolism Quiz

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are doing what of the following? A) Changing chemical energy into kinetic energy B) Changing kinetic energy into potential energy C) Changing chemical energy into potential energy D) Changing kinetic energy into chemical energy E) None of these choices are correct.

A) Changing chemical energy into kinetic energyCorrect

When a cell uses chemical energy to perform work, it couples this reaction with this reaction. A) Exergonic, endergonic B) Exergonic, spontaneous C) Endergonic, spontaneous D) Endergonic, exergonic E) Spontaneous, exergonic

A) Exergonic, endergonic

Which of the following is true of activation energy? It prevents the spontaneous breakdown of molecules in the cell. It cannot be overcome with the use of enzymes. It is higher with an enzyme. It may place chemical groups of the active site in position to catalyze the reaction. It is the amount of energy that must be produced by the reactants to end a chemical reaction.

A) It prevents the spontaneous breakdown of molecules in the cell.

Which of the following is a coenzyme? A) NADH B) iodine C) hydrogen ions D) zinc E) iron

A) NADH

Which of the following substances could be a cofactor? A) A protein B) NAD+ C) A polypeptide D) All of these choices are correct. E) None of these choices are correct.

B) NAD+

Kinetic energy differs from chemical energy in that ______. A) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules B) kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat C) kinetic energy depends on the movement of atoms, whereas chemical energy depends on the movement of molecules D) chemical energy is a particular form of kinetic energy E) kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement

A) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules

The processes of photosynthesis by producers and cellular respiration by consumers are complementary. During these energy conversions, some energy is A) lost in the form of heat. B) used to create light. C) created in the form of heat. D) All of the choices are correct. E) None of the choices are correct.

A) lost in the form of heat.

ATP is A) the energy currency of a cell B) produced during the phosphorylation of any organic compound C) produced by the destruction of ADP D) expended in the process of photosynthesis

A) the energy currency of a cell

The term "phosphorylation" refers to the transfer of a phosphate to a substrate - like ADP. subtraction of a phosphate from a substrate. use of an enzyme to break down ATP. second law of thermodynamics relating to phosphorous function. taking away of phosphate molecules from enzymes.

A) transfer of a phosphate to a substrate - like ADP.

Which of the following is not a way that enzymes speed reactions? They lower the activation energy. Active sites of some enzymes attract water, keeping it in the reaction. Entering an active site brings substrates in close physical proximity. An active site puts the substrates in the positions that favor the reaction. A shape change of the active site occurs when the substrate binds and enables the reaction.

B) Active sites of some enzymes attract water, keeping it in the reaction.

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action? A) Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell. B) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions. C) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. D) Elevated body temperatures will have no effect on enzyme-mediated reactions. E) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions.

B) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

Which one of the following statements concerning energy is false? A) Fireflies are able to take potential energy in the form of food and convert that energy into kinetic energy in the form of heat and light. B) Living systems convert heat energy into chemical energy to reduce entropy. C) During photosynthesis, plants convert kinetic energy into chemical energy. D) A gasoline engine converts chemical energy into kinetic energy. E) Energy transformations in cells are accompanied by the release of heat energy.

B) Living systems convert heat energy into chemical energy to reduce entropy.

The second law of thermodynamics states that____________. A) energy can be transformed into matter and, because of this, we can get something for nothing. B) energy tends to become increasingly dispersed and unusable. C) energy can be destroyed only during nuclear reactions, such as those that occur inside the sun. D) if energy is gained by one region of the universe, another place in the universe also must gain energy to maintain the balance of nature.

B) energy tends to become increasingly dispersed and unusable.

Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of A) positive feedback. B) feedback inhibition. C) irreversible inhibition. D) noncompetitive inhibition. E) competitive inhibition.

B) feedback inhibition.

Most of a cell's enzymes are ________. A) nucleic acids B) proteins C) lipids D) carbohydrates E) amino acids

B) proteins

ATP can be used as the cell's energy currency because of which of the following reasons? A)Endergonic reactions can be fueled by coupling them with the formation of ATP from ADP. B) Endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP. C)ATP is the most energy-rich small molecule in the cell. D) The regeneration of ATP from ADP can be fueled by coupling it with endergonic reactions. E) None of these choices are correct.

B) reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.

Coupling occurs when the energy released by an exergonic reaction is ______. A) used to decrease the entropy of the universe. B) used to drive an endergonic reaction. C) used to drive another exergonic reaction. D) lost as nonusable heat to the environment. E) All of the choices are correct.

B) used to drive an endergonic reaction.

Which of the following does not indicate the first law of thermodynamics. A) Orange trees absorbing energy from the sun and storing the energy in chemical bonds of starch and sugar. B) The wind blowing through a turbine that is used to generate electricity with a generator C) A cup of hot tea cooling over time. D) The glow of an incandescent bulb following the flow of electrons through a wire. E) A hydroelectric plant at a waterfall that is producing electricity.

C) A cup of hot tea cooling over time.

Which of the following is consistent with the laws of physics governing energy? A) A calorie of sunlight becomes a calorie of plant tissue that, eaten by you, becomes a calorie of heat lost in muscle "power." B) Chemical bonds are a case of converting energy to matter; breaking the bonds converts matter to energy. C) A molecule of glucose has less entropy than the individual carbon, hydrogen, and oxygen atoms that go into making it. D) You eat a "quarter-pounder" hamburger and assemble exactly a quarter-pound of additional body weight on your body. E) When a liter of gasoline is burned in a car engine, 100% of its energy goes into moving the car along the road.

C) A molecule of glucose has less entropy than the individual carbon, hydrogen, and oxygen atoms that go into making it.

Life's primary molecule used to store and release energy is ____. A) food B) entropy C) ATP D) heat E) water

C) ATP

Which statement describes the currently accepted theory of how an enzyme and its substrate fit together? A)The enzyme is like a key that fits into the substrate, which is like a lock. B) As the product is released, the enzyme breaks down. C) As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction. D) The active site is permanently changed by its interaction with the substrate. E) None of the choices are correct.

C) As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction.

which one of the following is true about the ATP molecule? A) None of the choices are correct B) It contains C) It contains a nitrogenous base molecule called adenine. D) Extremely stable bonds link the second and third phosphate groups. E) It contains the six-carbon sugar hexose.

C) It contains a nitrogenous base molecule called adenine.

When an enzyme catalyzes a reaction, A) It acts as a reactant B) It becomes a product C) It lowers the activation energy of the reaction D) It raises the activation energy of the reaction E) None of the choices are correct

C) It lowers the activation energy of the reaction

A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates which of the following? A) The first law of thermodynamics B) That some energy is destroyed in every energy conversion C) The second law of thermodynamics D) That energy transformations are typically 100% efficient E) None of these choices are correct.

C) The second law of thermodynamics

Two basic kinds of enzyme inhibitors are properly called ________. A) allosteric and functionally active B) induced fit and active site C) competitive and noncompetitive D) cofactors and induced fit models E) in-play and out-of-play

C) competitive and noncompetitive

The active site of an enzyme A) will react with only one substrate no matter how many molecules may resemble the shape of the substrate. B) is a specific bulge or protuberance on an enzyme. C) is a groove or crevice on the structure of the enzyme. D) rigidly resists any alteration of its shape. E) is where the coenzyme is located.

C) is a groove or crevice on the structure of the enzyme.

ATP is considered a high-energy compound because under cellular conditions, 7.3 kcal per mole of energy is released when a bond is broken between ______. A) the adenosine and the phosphate groups. B) the base adenine and the phosphate groups. C) the adenosine diphosphate and the third phosphate. D) the base adenine and the sugar ribose. E) All of the above bonds release energy as ATP is completely broken down.

C) the adenosine diphosphate and the third phosphate.

Heating inactivates enzymes by doing which of the following? A) By breaking the covalent bonds that hold the molecule together B) By causing enzyme molecules to stick together C) By removing phosphate groups from the enzymeIncorrect D) By changing the enzyme's three-dimensional shape E) None of these choices are correct.

D) By changing the enzyme's three-dimensional shape

Which type of potential energy is stored in molecules of food and gasoline? A) Light B) Heat C) Ionic D) Chemical E) Covalent

D) Chemical

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which explanation offers the most logical reason for this action? A) Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell. B) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. C) Elevated body temperatures easily break the covalent bonds linking biologically important molecules. This will cause a general breakdown of cell structures. D) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions. E) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions.

D) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

Which of the following statements are true for an energy barrier? A) It is the amount of energy that must be produced by the reactants to start a chemical reaction. B) It is lower than the energy of activation of a reaction. C) It is higher than the energy of activation of a reaction. D) It prevents the spontaneous breakdown of molecules in the cell. E) None of these choices are correct

D) It prevents the spontaneous breakdown of molecules in the cell.

A coenzyme is ____. A) an ionic cofactor that interacts with an enzyme to allow it to work. B) a protein cofactor that interacts with an enzyme to inhibit it. C) an ionic cofactor that interacts with an enzyme to inhibit it. D) a nonprotein organic cofactor that interacts with an enzyme to allow it to work. E) a protein cofactor that interacts with an enzyme to allow it to work.

D) a nonprotein organic cofactor that interacts with an enzyme to allow it to work.

The minimum amount of energy required to get a chemical reaction started is called ______ energy. A) chemical B) potential C) kinetic D) activation E) thermal

D) activation

Anything that prevents ATP formation will most likely A) result in the conversion of kinetic energy to potential energy. B) force the cell to rely on lipids for energy. C) have no effect on the cell. D) result in cell death. E) force the cell to rely on ADP for energy.

D) result in cell death.

According to __________, energy cannot be created or destroyed. the second law of thermodynamics A) Aristotle's first principle B) Einstein's law of relativity C) the third law of thermodynamics D) the first law of thermodynamics

D) the first law of thermodynamics

Which one of the following processes is endergonic? A) the release of heat from the breakdown of glucose B) the burning of wood C) cellular respiration D) the synthesis of glucose from carbon dioxide and water E) the breakdown of glucose

D) the synthesis of glucose from carbon dioxide and water

Enzymes are _______. A. influenced by temperature B. influenced by pH C. not influenced by salinity D. both a and b E. All of the choices are correct.

D. both a and b

How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor? A) Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants. B) Competitive inhibitors change the enzyme's tertiary structure; noncompetitive inhibitors cause polypeptide subunits to dissociate. C) Competitive inhibitors are inorganic substances such as metal ions; noncompetitive inhibitors are vitamins or vitamin derivatives. D) Competitive inhibitors bind to the enzyme reversibly; noncompetitive inhibitors bind to it irreversibly. E) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

E) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

Which statement about energy transformations is true? A) Living organisms decrease entropy in the universe as energy is transformed from light to chemical energy. B) Energy is constantly being created in the universe. C) In energy transformations, energy is conserved or recycled. D) Energy transformations decrease entropy in the universe. E) Entropy is constantly increasing in the universe.

E) Entropy is constantly increasing in the universe.

Which one of the following is false? A) Enzymes emerge unchanged from the reactions they catalyze. B) An enzyme binds to its substrate at the enzyme's active site. C) An enzyme's function depends on its three-dimensional shape. D) Enzymes are very specific for certain substrates. E) Enzymes are used up in chemical reactions.

E) Enzymes are used up in chemical reactions.