Exam 6: An Introduction to Metabolism

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 difference between the free-energy content of the reactants and the free-energy content of the products?

Which of the following reactions tend to require an input of energy?

Zinc,an essential trace element for most organisms,is required in the active site of the enzyme carboxypeptidase in order for the enzyme to function properly.The zinc most likely functions as a(n)

Which of the following reactions release energy?

Which of the descriptions below is an example of an exergonic reaction?

Hydrolysis of ATP releases energy,which ultimately results in the production of ADP and inorganic phosphate.What generally happens to the inorganic phosphate produced in the cytosol?

When chemical,transport,or mechanical work is performed by an organism,what happens to the heat that is generated?

Figure 6.1 -Which of the following is the most correct interpretation of Figure 6.1?

Figure 6.4 -Figure 6.4 illustratesvarious aspects of the free-energy change (ΔG)for the reaction A + B ↔ C + D.Which of the following best describes the forward reaction?

Figure 6.3 Activity of various enzymes (a)at various temperatures and (b)at various pH. -Which curves on the graphs in Figure 6.3 may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline hot spring at temperatures of 70°C or higher?

The ∆G for a particular enzyme-catalyzed reaction is -20 kcal/mol.If the amount of enzyme in the reaction is doubled,what will be the ∆G for the new reaction?

A chemical reaction that has a positive ΔG is best described as

Cooperativity is a form of allosteric activation in which

Cells use the ATP cycle shown in Figure 6.1 to perform which of the following processes?

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 the enzyme-catalyzed reaction?

Succinate dehydrogenase catalyzes the conversion of succinate to fumarate.The reaction is inhibited by malonic acid,which resembles succinate but cannot be acted upon by succinate dehydrogenase.Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of malonic acid.Which of the following statements regarding the molecules involved in this reaction is correct?

-For the enzyme-catalyzed reaction shown in Figure 6.2,which of these treatments will cause the greatest increase in the rate of the reaction if the initial reactant concentration is 1.0 micromolar?

Chemical equilibrium is relatively rare in living cells.Which of the following could be an example of a reaction at chemical equilibrium in a cell?

An aminoacyl-tRNA synthetase is the enzyme that catalyzes the attachment of a particular amino acid to its corresponding tRNA.This reaction requires energy from ATP.The enzyme initially binds the amino acid and ATP,but it is unable to bind the tRNA at this point.Which of the following would be a likely next step in the reaction by which the enzyme ultimately binds the tRNA and attaches the amino acid?

Which of the following processes would be an example of a catabolic pathway?