AP Biology Ch 6 - Introduction to Metabolism - Test Questions

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) Energy cannot be created or destroyed. (1ST law - principle of conservation of energy)

If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to A) add more of the enzyme. B) heat the solution to 90°C. C) add more substrate. D) add an allosteric inhibitor. E) add a noncompetitive inhibitor.

A) add more of the enzyme

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) dehydration reactions

Which of the following statements regarding enzymes is true? A) Enzymes decrease the free energy change of a reaction. B) Enzymes increase the rate of a reaction. C) Enzymes change the direction of chemical reactions. D) Enzymes are permanently altered by the reactions they catalyze. E) Enzymes prevent changes in substrate concentrations.

B) Enzymes increase the rate of a reaction.

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) It provides energy coupling between exergonic and endergonic reactions.

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) The organism ultimately must obtain all of the necessary energy for life from its environment.

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

Which of the following is likely to lead to an increase in the concentration of ATP in a cell? A) an increase in a cellʹs anabolic activity B) an increase in a cellʹs catabolic activity C) an increased influx of cofactor molecules D) an increased amino acid concentration E) the cellʹs increased transport of materials to the environment

B) an increase in a cellʹs catabolic activity

1) Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as __________ is to __________. A) exergonic; spontaneous B) exergonic; endergonic C) free energy; entropy D) work; energy E) entropy; enthalpy

B) exergonic; 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 systemʹs entropy D) the cellʹs energy equilibrium E) the condition of a cell that is not able to react

B) the heat content of a chemical system

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) They consume energy to build up polymers from monomers

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) an RNA nucleotide

The mathematical expression for the change in free energy of a system is △G =△H-T△S. Which of the following is (are) correct? A) △S is the change in enthalpy, a measure of randomness. B) △H is the change in entropy, the energy available to do work. C) △G is the change in free energy. D) T is the temperature in degrees Celsius.

C) △G is the change in free energy.

How can one increase the rate of a chemical reaction? A) Increase the activation energy needed. B) Cool the reactants. C) Decrease the concentration of the reactants. D) Add a catalyst. E) Increase the entropy of the reactants.

D) Add a catalyst

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) Every chemical reaction must increase the total entropy of the universe. (2nd law - every single transfer/transformation increases the entropy of universe)

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) It is lost to the environment.

According to the induced fit hypothesis of enzyme catalysis, which of the following IS correct? A) The binding of the substrate depends on the shape of the active site. B) Some enzymes change their structure when activators bind to the enzyme. C) A competitive inhibitor can outcompete the substrate for the active site. D) The binding of the substrate changes the shape of the enzymeʹs active site. E) The active site creates a microenvironment ideal for the reaction.

D) The binding of the substrate changes the shape of the enzymeʹs active site.

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) a food molecule made up of energy-rich

Whenever energy is transformed, there is always an increase in the A) free energy of the system. B) free energy of the universe. C) entropy of the system. D) entropy of the universe. E) enthalpy of the universe.

D) entropy of the universe. (entropy - a measure of disorder)

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) catabolism (catabolism = bigger into smaller)

What is the change in free energy of a system at chemical equilibrium? A) slightly increasing B) greatly increasing C) slightly decreasing D) greatly decreasing E) no net change

E) no net change