Energy & Enzymes Quick Check

Which of the following is true of metabolism in its entirety in all organisms?

• Metabolism uses all of an organism's resources.

• Metabolism consists of all the energy transformation reactions in an organism.

• Metabolism manages the increase of entropy in an organism.

• Metabolism depends on an organism's adequate hydration.

Tags

NGSS.HS-LS2-3

NGSS.HS-LS2-4

NGSS.HS-LS2-5

Whenever energy is transformed, there is always an increase in the

• free energy of the system.

• free energy of the universe.

• entropy of the universe.

• enthalpy of the system.

Which statement about metabolic pathways is true?

• Complex chemical transformations in the cell occur in a single reaction.

• Every reaction requires ATP.

• Each step in a metabolic pathway is regulated by a specific enzyme.

• Basic reactions vary drastically from organism to organism.

Which term most precisely describes the cellular process of breaking down large molecules into smaller

ones?

• anabolism

• catabolism

• dehydration

• catalysis

Which of the following is a statement of the first law of thermodynamics?

• Energy cannot be created or destroyed.

• The entropy of the universe is decreasing.

• Kinetic energy is stored energy that results from the specific arrangement of matter.

• The entropy of the universe is constant.

Which of the following is true for all exergonic reactions?

• The reaction proceeds with a net release of free energy.

• A net input of energy from the surroundings is required for the reactions to proceed.

• The products have more total energy than the reactants.

• The reactions are rapid.

Tags

NGSS.HS-PS1-4

To study the actions of the enzyme catalase on hydrogen peroxide, students performed the following experiment. Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water. The filtrate was stored on ice. The following hydrogen peroxide solutions were made: 1 percent, 5 percent, 10 percent, and 15 percent. Filter paper disks were soaked in the catalase filtrate and dropped into beakers containing the various solutions. The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction. The following data were obtained.

Which of the following best describes why the disks rose to the surface faster in the more concentrated hydrogen peroxide solutions?

• There was more enzyme present in the more concentrated solutions.

• A greater amount of heat was generated in the more concentrated solutions.

• The more concentrated solutions lowered the activation energy of the reaction.

• The higher substrate concentrations in the more concentrated solutions made the reaction proceed more rapidly.

Tags

NGSS.HS-PS1-5

During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a delta G of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the delta G for the new reaction?

• +40 kcal/mol

• 0 kcal/mol

• -40 kcal/mol

• -20 kcal/mol

Tags

NGSS.HS-PS1-4

Which of the following can be used to determine the rate of enzyme-catalyzed reactions?

• Rate of disappearance of the enzyme

• Rate of disappearance of the substrate

• Rate of disappearance of the product

• Change in volume of the solution

Tags

NGSS.HS-PS1-5

The diagram below shows energy changes in a specific chemical reaction with and without the addition of an enzyme to the reaction.

Which of the following questions can best be answered by the diagram?

• Does the addition of an enzyme reduce the activation energy required for a reaction?

• Does the addition of an enzyme result in the formation of covalent bonds?

• Does the addition of an enzyme produce a greater amount of products?

• Does the addition of an enzyme change the pathway for the reaction?

Tags

NGSS.HS-PS1-4