NEW
Font size
Worksheetsenzymes
Total questions: 9
Worksheet time: 5mins
Which of the following is an example of how enzymes are catalyst?
Enzymes can alter the free energy change (ΔG) for a chemical reaction.
Enzymes increase the free energy of the reactants to make the reaction go faster.
Enzymes provide the activation energy for the reactions they facilitate.
Enzymes lower the activation energy so that reactants absorb enough energy to reach transition state.
What statement best describes what happens during the catalytic cycle?
The enzyme breaks the substrate apart to prepare for the reaction.
The enzyme positions the substrate to increase access during a reaction.
The substrate uses enzyme energy to start the reaction.
The active site releases the substrate and replaces it with an inhibitor.
Which statement explains why the induced fit model is a more accurate description of enzyme/substrate bonding than the lock and key model?
Enzymes have active sites that fit most substrates.
Enzymes do not need active sites to bond to substrates.
Enzymes have rigid active sites with flexible sites for co-factors.
Enzymes do have flexible active sites that mold to substrates.
A chemical changes the shape of the active site of an enzyme. What will likely happen as a result of this chemical change?
The enzyme will be inhibited because the substrate cannot induce the proper fit.
The enzyme will be inhibited because a coenzyme cannot properly attach to the substrate.
The enzyme will catalyze the reaction but will be altered in the process.
The enzyme will be transformed into a coenzyme, halting the reaction.
Acetylcholinesterase is an enzyme that catalyzes the breakdown of the neurotransmitter acetylcholine. Which of the following explains why acetylcholinesterase cannot be used to catalyze the breakdown of other neurotransmitters, like norepinephrine?
It would require a level of activation energy too high for acetylcholinesterase to react with other neurotransmitters.
Binding with an alternate neurotransmitter would inhibit the reaction of the enzyme with acetylcholine.
Reacting with another neurotransmitter would halt the production of the enzyme and raise the overall activation energy.
Its shape determines the neurotransmitters that can reach its active center where activation energy is lowered.
A biologist wants to increase the rate of his chemical reaction but has a limited amount of enzyme. He continues to increase the substrate concentration instead. Eventually, the reaction rate levels off, and he can't get it to go any faster. What prevented the rate from increasing further?
The solution ran out of enzyme
The substrate concentration reached Vmax
The products of the reaction inhibited the enzyme
The solution ran out of reactants
Which of the following best characterizes the reaction below?
AB + energy → A + B
Catabolism
Endergonic reaction
Exergonic reaction
Hydrolysis
Ammonia, NH3, is used in numerous industrial processes, including the production of pharmaceuticals such as sulfonamide and antimalarials and vitamins such as the B vitamins. The equilibrium equation for the synthesis of ammonia (sometimes known as the Haber process) is N2(g) + 3H2(g) ↔ 2NH3(g).
What will happen to the rates of the forward and reverse reactions when a catalyst is added?
Forward rate increases; reverse rate decreases.
Both forward and reverse rates increase.
Both forward and reverse rates decrease.
Forward rate decreases; reverse rate increases.
A series of enzymes catalyze the reaction X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A functions as
an allosteric inhibitor
a coenzyme
a competitive inhibitor
an intermediate
