Biochem C785 Enzymes
Which property of enzymes is illustrated in the final step of the enzymatic cycle?
Enzymes are specific.
Enzymes increase the reaction rate for a reaction.
Enzymes lower the activation energy for a reaction.
Enzymes are reusable. - CORRECT ANSWERS Enzymes are reusable
In the final step of the enzymatic cycle, the product is released and the enzyme is able
to bind to a new substrate and begin the cycle again.
In the enzyme cycle, which step immediately follows induced fit?
Formation of the enzyme-substrate complex
Formation of the enzyme-molecule complex
Formation of the enzyme-product complex
Release of the product and enzyme complex - CORRECT ANSWERS Formation
of the enzyme-product complex
Which type of inhibition occurs when a particular drug binds to the active site of an
enzyme?
Irreversible
Noncompetitive
Uncompetitive
Competitive - CORRECT ANSWERS competitive
Salivary amylase, an enzyme responsible for partial digestion of carbohydrates, has
optimum activity at a pH value of 6.8.
What is the impact on the activity if the pH is decreased to 4.0?
Slightly increase
Significantly increase
Slightly decrease
Significantly decrease - CORRECT ANSWERS slightly decrease
Low levels of glutathione are associated with certain types of ovarian and breast
cancers. In the synthesis of glutathione, glutathione accumulates in the cell, binding to
an enzyme in the pathway and temporarily preventing the synthesis of glutathione.
Which type of inhibition is described by this scenario?
Feedback
Uncompetitive
Allosteric
Competitive - CORRECT ANSWERS Feedback
Lipase is an enzyme with an optimum temperature of 98.6°F and an optimum pH of 7.0
in the duodenum in the human body. If a person is experiencing a fever of 99.8°F, what
will increase the activity of the lipase enzyme?
Increase in temperature
, Biochem C785 Enzymes
Decrease of the substrate of the enzyme
Increase of pH of duodenum to 8.0
Decrease in temperature - CORRECT ANSWERS Decrease in temperature
The enzyme glucokinase only binds its substrate glucose and converts glucose into the
product glucose-6-phosphate. Which property of enzymes is described by this
scenario?
Reaction rate
Activation energy
Induced fit
Specificity - CORRECT ANSWERS Specificity
Enzymes have a high degree of specificity. They will bind to one specific class of
molecules and usually catalyze only one type of reaction.
Low levels of glutathione are associated with neurological, immunological, and
cardiovascular impairments. Two enzymatic reactions are involved in the synthesis of
glutathione. In the second enzymatic reaction, glutathione synthetase converts glycine
to glutathione. What would potentially decrease risks associated with low levels of
glutathione?
Uncompetitive inhibitor of glutathione synthetase
Increasing the amount of glycine in the diet
Noncompetitive inhibitor of glutathione synthetase
Decreasing the amount of glycine in the diet - CORRECT ANSWERS Increasing
the amount of glycine in the diet
Which class of enzymes impacts protein function by temporarily removing a phosphate?
Synthetase
Phosphatase
Esterase
Kinase - CORRECT ANSWERS Phosphatase
How does the activation energy of enzyme-catalyzed reactions compare to those of
corresponding uncatalyzed reactions?
The activation energy of enzyme-catalyzed reactions are lower than the uncatalyzed
reaction
The activation energy of enzyme-catalyzed reactions are higher than uncatalyzed
reactions
The activation energy of enzyme-catalyzed reactions are the same as uncatalyzed
reactions
The activation energy of the enzyme-catalyzed reactions only changes in response to
temperature. - CORRECT ANSWERS The activation energy of enzyme-catalyzed
reactions are lower than the uncatalyzed reaction
Which property of enzymes is illustrated in the final step of the enzymatic cycle?
Enzymes are specific.
Enzymes increase the reaction rate for a reaction.
Enzymes lower the activation energy for a reaction.
Enzymes are reusable. - CORRECT ANSWERS Enzymes are reusable
In the final step of the enzymatic cycle, the product is released and the enzyme is able
to bind to a new substrate and begin the cycle again.
In the enzyme cycle, which step immediately follows induced fit?
Formation of the enzyme-substrate complex
Formation of the enzyme-molecule complex
Formation of the enzyme-product complex
Release of the product and enzyme complex - CORRECT ANSWERS Formation
of the enzyme-product complex
Which type of inhibition occurs when a particular drug binds to the active site of an
enzyme?
Irreversible
Noncompetitive
Uncompetitive
Competitive - CORRECT ANSWERS competitive
Salivary amylase, an enzyme responsible for partial digestion of carbohydrates, has
optimum activity at a pH value of 6.8.
What is the impact on the activity if the pH is decreased to 4.0?
Slightly increase
Significantly increase
Slightly decrease
Significantly decrease - CORRECT ANSWERS slightly decrease
Low levels of glutathione are associated with certain types of ovarian and breast
cancers. In the synthesis of glutathione, glutathione accumulates in the cell, binding to
an enzyme in the pathway and temporarily preventing the synthesis of glutathione.
Which type of inhibition is described by this scenario?
Feedback
Uncompetitive
Allosteric
Competitive - CORRECT ANSWERS Feedback
Lipase is an enzyme with an optimum temperature of 98.6°F and an optimum pH of 7.0
in the duodenum in the human body. If a person is experiencing a fever of 99.8°F, what
will increase the activity of the lipase enzyme?
Increase in temperature
, Biochem C785 Enzymes
Decrease of the substrate of the enzyme
Increase of pH of duodenum to 8.0
Decrease in temperature - CORRECT ANSWERS Decrease in temperature
The enzyme glucokinase only binds its substrate glucose and converts glucose into the
product glucose-6-phosphate. Which property of enzymes is described by this
scenario?
Reaction rate
Activation energy
Induced fit
Specificity - CORRECT ANSWERS Specificity
Enzymes have a high degree of specificity. They will bind to one specific class of
molecules and usually catalyze only one type of reaction.
Low levels of glutathione are associated with neurological, immunological, and
cardiovascular impairments. Two enzymatic reactions are involved in the synthesis of
glutathione. In the second enzymatic reaction, glutathione synthetase converts glycine
to glutathione. What would potentially decrease risks associated with low levels of
glutathione?
Uncompetitive inhibitor of glutathione synthetase
Increasing the amount of glycine in the diet
Noncompetitive inhibitor of glutathione synthetase
Decreasing the amount of glycine in the diet - CORRECT ANSWERS Increasing
the amount of glycine in the diet
Which class of enzymes impacts protein function by temporarily removing a phosphate?
Synthetase
Phosphatase
Esterase
Kinase - CORRECT ANSWERS Phosphatase
How does the activation energy of enzyme-catalyzed reactions compare to those of
corresponding uncatalyzed reactions?
The activation energy of enzyme-catalyzed reactions are lower than the uncatalyzed
reaction
The activation energy of enzyme-catalyzed reactions are higher than uncatalyzed
reactions
The activation energy of enzyme-catalyzed reactions are the same as uncatalyzed
reactions
The activation energy of the enzyme-catalyzed reactions only changes in response to
temperature. - CORRECT ANSWERS The activation energy of enzyme-catalyzed
reactions are lower than the uncatalyzed reaction
