Exam 6: An Introduction to Metabolism

An enzyme-catalyzed reaction is conducted in a test tube with a fixed amount of enzyme.Increasing the enzyme concentration in the test tube may overcome the effect of which of the following conditions?

A noncompetitive inhibitor decreases the rate of an enzymatic reaction by

Which of the following statements is representative of the second law of thermodynamics?

Why might a severe fever result in death if it is not brought under control?

An enzyme-catalyzed reaction is conducted in a test tube with a fixed amount of enzyme.Increasing the substrate concentration in the test tube may overcome the effect of which of the following conditions?

ATP hydrolysis in a test tube releases only about half as much energy as ATP hydrolysis in the cell.Which of the following statements is the best explanation for this observation?

Which of the following statements about a system at chemical equilibrium is true?

Some of the drugs used to treat HIV patients are competitive inhibitors of the HIV reverse transcriptase enzyme.Unfortunately,the high mutation rate of HIV means that the virus rapidly acquires mutations with amino acid changes that make them resistant to these competitive inhibitors.Where in the reverse transcriptase enzyme would such amino acid changes most likely occur in drug-resistant viruses?

Energy transformations in organisms are always associated with

What is the difference (if any)between the structure of ATP and the structure of the A nucleoside triphosphate used to make DNA?

Some bacteria are metabolically active in hot springs because

The free-energy change for the hydrolysis of ATP to ADP + ℗_i,under standard conditions (1 M concentration of both reactants and products)is -7.3 kcal/mol.However,in the cytoplasm of the cell,the free-energy change is about -13 kcal/mol.Based on this observation,what would you predict the free-energy change for the reverse reaction (formation of ATP from ADP and ℗_i)would be under cellular conditions?

Figure 6.3 Activity of various enzymes (a)at various temperatures and (b)at various pH. -Which temperature and pH profile curves on the graphs in Figure 6.3 were most likely generated from analysis of an enzyme from a human stomach,where conditions are strongly acidic?

The active site of an enzyme is the region that

Anabolic pathways share which of the following characteristics?

Figure 6.4 -Figure 6.4 illustrates various aspects of the free-energy change (ΔG)for the reaction A + B ↔ C + D.Which of the following changes in free-energy represents the activation energy required for a noncatalyzed reaction?

Figure 6.4 -Figure 6.4 illustrates various aspects of the free-energy change (ΔG)for the reaction A + B ↔ C + D.Which of the following changes in free-energy would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

If an enzyme in solution is saturated with substrate,the most effective way to obtain a faster yield of products is to

Figure 6.4 -Figure 6.4 illustrates various aspects of the free-energy change (ΔG)for the reaction A + B ↔ C + D.Which of the following represents change in free-energy for the reverse reaction,C + D → A + B?

Which of the following statements about enzyme-catalyzed reactions is true?