Mastering Biology Ch 8
The following question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the activation energy needed for the enzyme-catalyzed reverse reaction, C + D → A + B, in the figure?
A
Which of the following statements describes enzyme cooperativity?
A substrate molecule bound to an active site of one subunit promotes substrate binding to the active site of other subunits.
The following question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following in the figure would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?
D
The following question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the difference between the free-energy content of the reactants and the free-energy content of the products in the figure?
D
The following question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following represents the ΔG of the reaction in the figure?
D
Which of the following is a statement of the first law of thermodynamics?
Energy cannot be created or destroyed.
Which of the following statements regarding enzymes is true?
Enzymes increase the rate of a reaction by lowering the activation energy barrier.
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
It is lost to the environment.
Which of the following is NOT a way in which an enzyme can speed up the reaction that it catalyzes?
The active site can provide heat from the environment that raises the energy content of the substrate. An enzyme cannot extract heat from the environment to speed a reaction. It can only lower the activation energy barrier so that more substrates have the energy to react.
According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
The binding of the substrate changes the shape of the enzyme's active site.
Which of the following statements about feedback regulation of a metabolic pathway is correct?
The final product of a metabolic pathway is usually the compound that regulates the pathway. It is quite common that the end product of the pathway controls the overall rate of the pathway
Which of the following statements is true about enzyme-catalyzed reactions?
The reaction is faster than the same reaction in the absence of the enzyme.
Which of the following is true for all exergonic reactions?
The reaction proceeds with a net release of free energy.
Which of the following is (are) true for anabolic pathways?
They consume energy to build up polymers from monomers.
If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to
add more of the enzyme.
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's
activation energy.
The following question is based on the reaction A + B ↔ C + D shown in the figure. Which of the following terms best describes the forward reaction in the figure?
c. exergonic, Δ G < 0
Which temperature and pH profile curves on the graphs were most likely generated from analysis of an enzyme from a human stomach where conditions are strongly acid?
curves 1 and 4
Whenever energy is transformed, there is always an increase in the
entropy of the universe.
Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _______ is to _______.
exergonic; endergonic
Enzymes are described as catalysts, which means that they _____.
increase the rate of a reaction without being consumed by the reaction
The active site of an enzyme is the region that
is involved in the catalytic reaction of the enzyme.
A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because
the activation energy barrier for this reaction cannot easily be surmounted at room temperature.
Some bacteria are metabolically active in hot springs because
their enzymes have high optimal temperatures.
