Biochemistry I Module of the MCAT Self Prep eCourse: Lesson 2: Enzym
(Pro)
Study online at https://quizlet.com/_3vhib6
1. Lesson 2: Enzymes: Lesson 2: Enzymes
2. DNA replication, the TCA cycle and the expression of genes are examples of
reactions that can be sped up by which type of proteins?
(A) Transport
(B) Globular
(C) Denatured
(D) Catalytic: (D) Catalytic
DNA replication, the TCA cycle and the expression of genes are examples of reactions that can be sped up by the use
of Enzymes, which are also known as Catalytic Proteins.
3. *CRB* Which of the following can Catalysts and Enzymes change for a reac-
tion?
I. Gibbs Free Energy
II. Equilibrium
III. Rate of Reaction
(A) III only
(B) I and II only
(C) II and III only
(D) I, II and III: (A) III only
Catalysts and Enzymes only change the Rate of the Reactions! They do NOT affect the equilibrium position or the Gibbs
Free Energy.
4. *CRB* Compare Enzymes and Catalysts.: Catalysts are any material that are not used up in a
reaction, but can speed up the process of a reaction.
Enzymes are Biological Catalysts made of proteins. Also note that there are Ribozymes (RNA that can have catalytic
functions similar to protein enzymes).
5. What is the primary role of enzymes?
, Biochemistry I Module of the MCAT Self Prep eCourse: Lesson 2: Enzym
(Pro)
Study online at https://quizlet.com/_3vhib6
(A) Increase the stability of the products.
(B) Increase the stability of the reactants.
(C) Increase the rate of a reaction.
(D) Decrease the change in Gibb's Free Energy from reactants to products.: (C)
Increase the rate of a reaction.
An enzymes primary role is to increase the rate of a reaction. This is often done via increasing the stability of
intermediates in the reaction.
6. True or False? The following reaction requires the enzyme Carbonic Anhy-
drase in order to proceed: H2O + CO2 <--> H2CO3: False. This reaction can still occur without
Carbonic Anhydrase. Carbonic Anhydrase will simply speed up this reaction. This is why soda will fizz MORE when it hits
your tongue.
7. In a decarboxylation reaction where a carboxy (CO2) group is being removed
from a molecule, a lot of electrons move around. What kind of catalytic strategy
would help this reaction go faster?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (C) Covalent Catalysis
A covalent catalysis would help this reaction go faster because the enzyme can act as an electron carrier (electron sink)
by covalently binding to its target molecule, thus helping with the transfer of electrons.
8. *CRB* A certain decarboxylation enzyme is very particular with both the
substrates that it will react with and the type of reaction that it will promote.
Does this meet the criteria to be an example of Enzyme Specificity?: Because a given
enzyme is being selective in both the substrates it will work with and the type of reaction it is promoting, this is a prime
example of Enzyme Specificity.
9. If you look at the keto-enol tautomerization reaction, a proton is moved from
a carbon atom to an oxygen atom. What kind of catalysis would help this
reaction go faster? Why?
, Biochemistry I Module of the MCAT Self Prep eCourse: Lesson 2: Enzym
(Pro)
Study online at https://quizlet.com/_3vhib6
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (A) Acid/Base Catalysis
Acid/base catalysis would help this reaction go faster because the enzyme can function as a proton carrier. The enzyme
can direct the proton's movement much more efficiently than if the proton were free floating.
10. DNA polymerase stabilizes DNA's negative charge via what catalytic strate-
gy?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (B) Electrostatic Catalysis
DNA polymerase utilizes electrostatic catalysis by using positively charged Mg to stabilize the negative phosphate charge
on DNA, making it easier to work with.
11. Changing the pH will most likely influence enzymes involved in which of the
following types of reactions?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (A) Acid/base Catalysis
Changing the pH will often affect enzymes involved in acid/base catalysis reactions, involving stabilizing charges, or
transfer of electrons.
12. Describe how enzymes utilize both proximity and orientation effects to
speed up reactions: Enzymes are able to bring 2 molecules close together (proximity effects) in the correct
orientation (orientation effects) thus increasing successful molecule collisions, generating faster reactions.
(Pro)
Study online at https://quizlet.com/_3vhib6
1. Lesson 2: Enzymes: Lesson 2: Enzymes
2. DNA replication, the TCA cycle and the expression of genes are examples of
reactions that can be sped up by which type of proteins?
(A) Transport
(B) Globular
(C) Denatured
(D) Catalytic: (D) Catalytic
DNA replication, the TCA cycle and the expression of genes are examples of reactions that can be sped up by the use
of Enzymes, which are also known as Catalytic Proteins.
3. *CRB* Which of the following can Catalysts and Enzymes change for a reac-
tion?
I. Gibbs Free Energy
II. Equilibrium
III. Rate of Reaction
(A) III only
(B) I and II only
(C) II and III only
(D) I, II and III: (A) III only
Catalysts and Enzymes only change the Rate of the Reactions! They do NOT affect the equilibrium position or the Gibbs
Free Energy.
4. *CRB* Compare Enzymes and Catalysts.: Catalysts are any material that are not used up in a
reaction, but can speed up the process of a reaction.
Enzymes are Biological Catalysts made of proteins. Also note that there are Ribozymes (RNA that can have catalytic
functions similar to protein enzymes).
5. What is the primary role of enzymes?
, Biochemistry I Module of the MCAT Self Prep eCourse: Lesson 2: Enzym
(Pro)
Study online at https://quizlet.com/_3vhib6
(A) Increase the stability of the products.
(B) Increase the stability of the reactants.
(C) Increase the rate of a reaction.
(D) Decrease the change in Gibb's Free Energy from reactants to products.: (C)
Increase the rate of a reaction.
An enzymes primary role is to increase the rate of a reaction. This is often done via increasing the stability of
intermediates in the reaction.
6. True or False? The following reaction requires the enzyme Carbonic Anhy-
drase in order to proceed: H2O + CO2 <--> H2CO3: False. This reaction can still occur without
Carbonic Anhydrase. Carbonic Anhydrase will simply speed up this reaction. This is why soda will fizz MORE when it hits
your tongue.
7. In a decarboxylation reaction where a carboxy (CO2) group is being removed
from a molecule, a lot of electrons move around. What kind of catalytic strategy
would help this reaction go faster?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (C) Covalent Catalysis
A covalent catalysis would help this reaction go faster because the enzyme can act as an electron carrier (electron sink)
by covalently binding to its target molecule, thus helping with the transfer of electrons.
8. *CRB* A certain decarboxylation enzyme is very particular with both the
substrates that it will react with and the type of reaction that it will promote.
Does this meet the criteria to be an example of Enzyme Specificity?: Because a given
enzyme is being selective in both the substrates it will work with and the type of reaction it is promoting, this is a prime
example of Enzyme Specificity.
9. If you look at the keto-enol tautomerization reaction, a proton is moved from
a carbon atom to an oxygen atom. What kind of catalysis would help this
reaction go faster? Why?
, Biochemistry I Module of the MCAT Self Prep eCourse: Lesson 2: Enzym
(Pro)
Study online at https://quizlet.com/_3vhib6
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (A) Acid/Base Catalysis
Acid/base catalysis would help this reaction go faster because the enzyme can function as a proton carrier. The enzyme
can direct the proton's movement much more efficiently than if the proton were free floating.
10. DNA polymerase stabilizes DNA's negative charge via what catalytic strate-
gy?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (B) Electrostatic Catalysis
DNA polymerase utilizes electrostatic catalysis by using positively charged Mg to stabilize the negative phosphate charge
on DNA, making it easier to work with.
11. Changing the pH will most likely influence enzymes involved in which of the
following types of reactions?
(A) Acid/base Catalysis
(B) Electrostatic Catalysis
(C) Covalent Catalysis
(D) Proximity/Orientation Catalysis: (A) Acid/base Catalysis
Changing the pH will often affect enzymes involved in acid/base catalysis reactions, involving stabilizing charges, or
transfer of electrons.
12. Describe how enzymes utilize both proximity and orientation effects to
speed up reactions: Enzymes are able to bring 2 molecules close together (proximity effects) in the correct
orientation (orientation effects) thus increasing successful molecule collisions, generating faster reactions.
