Chapter 16 Multiple-choice questions

* not completed

. The rate of removal of alcohol from the bloodstream stays the same, regardless of the concentration of blood alcohol. What term do we use to describe this reaction?

A zeroth order reaction correct incorrect

A first order reaction correct incorrect

A second order reaction correct incorrect

* not completed

. The concentration of a reactant is measured at two time intervals as a reaction proceeds. At the first time interval, the concentration of the reactant is 0.5 mol L^-1; 20 seconds later, the concentration is 0.45 mol L^-1. At what rate is the reactant being consumed?

0.0225 mol L^-1 s^-1 correct incorrect

0.0025 mol L^-1 s^-1 correct incorrect

0.05 mol L^-1 s^-1 correct incorrect

0.025 mol L^-1 s^-1 correct incorrect

* not completed

. A spontaneous reaction doesn't have an activation energy. True or false?

True correct incorrect

False correct incorrect

* not completed

. Look at the following diagram, which depicts the energy diagram for a chemical reaction. Which point on the diagram represents the point at which the transition state exists?

A correct incorrect

B correct incorrect

C correct incorrect

D correct incorrect

* not completed

. Which of the following statements regarding the use of catalysts is false?

Catalysts lower the activation energy for a reaction correct incorrect

Catalysts increase the proportion of molecules that possess sufficient energy to clear the activation energy barrier correct incorrect

Catalysts increase the number of reactions that can happen spontaneously correct incorrect

Catalysts provide an alternative reaction pathway from reactant to product correct incorrect

* not completed

. Enzyme–catalysed reactions do not involve a transition state. True or false?

True correct incorrect

False correct incorrect

* not completed

. Which one of the following statements regarding V_max and K_M is false?

V_max is the maximum rate at which a particular enzyme-catalysed reaction can proceed. correct incorrect

K_M is the concentration of substrate at which the rate of the reaction reaches V_max correct incorrect

A small value of K_M tells us that an enzyme binds strongly to its substrate correct incorrect

A large value of K_M tells us that an enzyme shows little specificity for a given substrate correct incorrect

* not completed

. Which of the following statements regarding enzymes is false?

A given enzyme catalyses just one type of reaction correct incorrect

While most enzymes are proteins, some are composed of RNA correct incorrect

The activity of enzymes is typically impaired at high temperatures correct incorrect

Enzymes act to lower the activation energy of a reaction by stabilising the transition state, but do not participate chemically in the reaction correct incorrect

* not completed

. Which of the following is not the name of a graph used to experimentally determine the values of K_M and V_max?

Michaelis-Menten correct incorrect

Lineweaver-Burk correct incorrect

Hanes correct incorrect

* not completed

. A reversible inhibitor is found to increase the K_M for a reaction but has no effect on V_max. To which class of reversible inhibitor does it belong?

Noncompetitive correct incorrect

Competitive correct incorrect

Uncompetitive correct incorrect

* not completed

. The following graph shows the velocity of an enzyme-catalysed reaction as the temperature increases. True or false?

True correct incorrect

False correct incorrect