AP BIOLOGY UNIT 3 CELLULAR ENERGETICS
PRACTICE TEST (MULTIPLE CHOICE)
What is the monomer that makes up an enzyme? - ANS -Amino acids
(proteins)
How does a substrate bind to an enzyme? - ANS -Via its active site;
When the substrate enters the active site, it forms a weak bond with
the enzyme, inducing a shape change on the enzyme. This change
allows additional weak bonds to form, causing the active site to enfold
the substrate and hold it in place.
What happens after the substrate binds to the enzyme? - ANS -There is
a slight shape change in the enzyme when the active site of the enzyme
interacts with the chemical groups of the substrate. This shape changes
allows the enzyme to fit better to the substrate.
What is the function of an enzyme? - ANS -Catalyze chemical reactions
How does the enzyme complete its function? - ANS -Lower the
activation energy so that the reactants can absorb enough energy to
reach the transition state
,How does an enzyme affect the rate of biological reactions? - ANS -
Speeds them up; lowers the activation energy so that the reaction is
faster
What is an enzyme-catalyzed reaction? - ANS -A reaction that uses an
enzyme to catalyze the rate of the reaction
How is the activation energy of an enzyme-catalyzed reaction and an
uncatalyzed reaction different? - ANS -The activation energy is lower in
an enzyme-catalyzed reaction and higher in an uncatalyzed reaction
How is the change in free energy of an enzyme-catalyzed reaction and
an uncatalyzed reaction different? - ANS -Enzymes do not affect the
Gibbs free energy of a reaction. That means that they do not increase or
decrease how much products are formed and how much reactants are
used up nor do they increase or decrease the free energy values of the
products and reactants.
How is the reaction rate of an enzyme-catalyzed reaction and an
uncatalyzed reaction different? - ANS -The reaction rate of an enzyme-
catalyzed rxn is much faster.
, Identify two conditions that affect the structure of an enzyme. What
happens to the structure of the enzyme in these conditions? - ANS -
Temperature: thermal agitation of the enzyme molecule disrupts the
hydrogen bonds, ionic bonds, and other weak interactions that stabilize
the active shape of the enzyme, and the protein molecule eventually
denatures.
pH: would be denatured in unsuitable pH
How does a change in structure affect the function of an enzyme? - ANS
-If the structure of the enzyme changes then the function will also
change (it won't be functional).
Predict the three different possible outcomes when there is a change in
structure of an enzyme. - ANS -Active site will be affected and substrate
cannot bind; enzyme's function is impaired; enzyme is denatured
What is denaturation? - ANS -Alteration of a protein shape through
some form of external stress (for example, by applying heat, acid or
alkali), in such a way that it will no longer be able to carry out its cellular
function.
True or False? Denaturation can be reversible. - ANS -True
PRACTICE TEST (MULTIPLE CHOICE)
What is the monomer that makes up an enzyme? - ANS -Amino acids
(proteins)
How does a substrate bind to an enzyme? - ANS -Via its active site;
When the substrate enters the active site, it forms a weak bond with
the enzyme, inducing a shape change on the enzyme. This change
allows additional weak bonds to form, causing the active site to enfold
the substrate and hold it in place.
What happens after the substrate binds to the enzyme? - ANS -There is
a slight shape change in the enzyme when the active site of the enzyme
interacts with the chemical groups of the substrate. This shape changes
allows the enzyme to fit better to the substrate.
What is the function of an enzyme? - ANS -Catalyze chemical reactions
How does the enzyme complete its function? - ANS -Lower the
activation energy so that the reactants can absorb enough energy to
reach the transition state
,How does an enzyme affect the rate of biological reactions? - ANS -
Speeds them up; lowers the activation energy so that the reaction is
faster
What is an enzyme-catalyzed reaction? - ANS -A reaction that uses an
enzyme to catalyze the rate of the reaction
How is the activation energy of an enzyme-catalyzed reaction and an
uncatalyzed reaction different? - ANS -The activation energy is lower in
an enzyme-catalyzed reaction and higher in an uncatalyzed reaction
How is the change in free energy of an enzyme-catalyzed reaction and
an uncatalyzed reaction different? - ANS -Enzymes do not affect the
Gibbs free energy of a reaction. That means that they do not increase or
decrease how much products are formed and how much reactants are
used up nor do they increase or decrease the free energy values of the
products and reactants.
How is the reaction rate of an enzyme-catalyzed reaction and an
uncatalyzed reaction different? - ANS -The reaction rate of an enzyme-
catalyzed rxn is much faster.
, Identify two conditions that affect the structure of an enzyme. What
happens to the structure of the enzyme in these conditions? - ANS -
Temperature: thermal agitation of the enzyme molecule disrupts the
hydrogen bonds, ionic bonds, and other weak interactions that stabilize
the active shape of the enzyme, and the protein molecule eventually
denatures.
pH: would be denatured in unsuitable pH
How does a change in structure affect the function of an enzyme? - ANS
-If the structure of the enzyme changes then the function will also
change (it won't be functional).
Predict the three different possible outcomes when there is a change in
structure of an enzyme. - ANS -Active site will be affected and substrate
cannot bind; enzyme's function is impaired; enzyme is denatured
What is denaturation? - ANS -Alteration of a protein shape through
some form of external stress (for example, by applying heat, acid or
alkali), in such a way that it will no longer be able to carry out its cellular
function.
True or False? Denaturation can be reversible. - ANS -True
