5 Written questions
5 Matching questions
- Which of the following is NOT a form of potential energy?
B. water in a dam
C. a muscle contracting
D. All of the choices are not potential energy.
- Which statement is NOT true about the effects of various conditions on the activity of an enzyme?
A. Higher temperatures generally increase the activity of an enzyme up to a point.
B. Above a certain range of temperatures, the protein of an enzyme is denatured.
C. A change in pH can cause an enzyme to be inactivated.
D. An enzyme's activity is generally reduced by an increase in substrate concentration.
E. When sufficient substrate is available, the active site will nearly always be occupied.
- Which form of energy is NOT correctly associated with the related example?
A. kinetic energy: fat molecules
B. kinetic energy: movement of muscles
C. chemical energy: glucose
D. potential energy: water held behind a dam
E. potential energy: ATP
- 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 base adenine and the sugar ribose.
B. the adenosine and the phosphate groups.
C. the base adenine and the phosphate groups.
D. the adenosine diphosphate and the third phosphate.
E. All of the bonds release energy as ATP is completely broken down.
- While eating a container of yogurt, you have to leave, so you store the yogurt in the refrigerator. A day later you return and find the surface of the yogurt is no longer smooth but has broken into several liquified products. You correctly guess that enzymes from your saliva, via the spoon, have continued digesting the yogurt in your absence. What will happen over time?
A. The reaction will soon stop because the amount of saliva is small, and you would have to add more saliva to continue the degradation.
B. The reaction will continue, since the enzyme is not consumed by the reaction.
C. The reaction will continue until half is digested and then stop because the reaction between substrate and product will be balanced.
D. Absolutely no degradation of the yogurt will occur naturally unless in the presence of this enzyme.
- a C. a muscle contracting
- b D. the adenosine diphosphate and the third phosphate.
- c D. An enzyme's activity is generally reduced by an increase in substrate concentration.
- d B. The reaction will continue, since the enzyme is not consumed by the reaction.
- e A. kinetic energy: fat molecules
5 Multiple choice questions
- E. are about twelve enzymes, at least one responsible for each step in the metabolic pathway.
- D. Some useful energy is lost as heat whenever an energy transfer occurs.
- D. D refers to the product.
- E. Both taking lactase enzyme and avoiding all dairy products would be correct.
- B. used to drive an endergonic reaction.
5 True/False questions
Energy coupling of endergonic and exergonic reactions within cells
A. permits biological reactions to proceed at temperatures consistent with life.
B. uses heat released by one reaction to fuel the other reaction.
C. utilizes ATP to carry energy between the exergonic and endergonic reactions.
D. All of the choices are correct. → D. All of the choices are correct.
Study the figure at right. What does the letter A depict?
A. Energy of the reactant
B. Energy of the products
C. Energy of activation
D. Substrate concentration → C. Energy of reactants; Energy of products
In this pathway, B C is coupled with ADP ATP. Categorize the reactions as endergonic or exergonic.
A. B C is endergonic and ADP ATP is exergonic.
B. ADP ATP is endergonic and B C is exergonic.
C. Both B C and ADP ATP are endergonic.
D. Both B C and ADP ATP are exergonic. → B. ADP ATP is endergonic and B C is exergonic.
Feedback inhibition is the process that turns off an early enzyme in a metabolic pathway as the result of inhibitory actions of a product of the pathway.
True False → D. As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction.
The activity of an enzyme might be increased by all of the following except ________?
A. increase in substrate concentration.
B. a vitamin.
C. 2-4 degree increase in temperature.
D. lead. → B. Reactions that occur spontaneously are those that increase the amount of useful energy in a system.