UNE BIOCHEMISTRY 2026 CORE EXAM TEST QUESTIONS
AND ANSWERS GUARANTEE A+
✔✔Heat can be generated by brown adipose tissue in hibernating mammals. Which of
the following is most likely the mechanism by which this occurs?
a.) Increased ATP production by ATP synthase
b.) Expression of a protein that uncouples the ETC
c.) An increased pH gradient across the inner mitochondrial membrane
d.) A decrease in oxygen consumption - ✔✔Expression of a protein that uncouples the
ETC (B)
✔✔Allosteric activators of hemoglobin will increase binding through what mechanism? -
✔✔Binding the protein, and keeping it in the "R" conformation
✔✔An enzyme has a mutation within the substate binding site that reduces the binding
of the coenzyme needed for covalent catalysis. What is likely to result as a
consequence of this mutation? - ✔✔The enzyme will not be able to form the transition
state complex
✔✔How do most enzymes reduce activation energy needed to move a reaction
forward? - ✔✔Providing an active site most complimentary to the transition state
✔✔Under which energy conditions, AMP will bind to phosphofructokinase 1 (PFK1) and
glycogen phosphorylase at site unique of the active site. This enhances the activity of
these enzymes. This is an example of which of the following types of enzyme
regulation?
a.) Allosteric activation
b.) Allosteric inhibition
c.) Competitive inhibition
d.) Covalent modification - ✔✔Allosteric activation (A)
✔✔Which of the following best describes an enzyme inhibitor that increases the Km, but
does not change the V-max?
a.) Inhibition by covalent modification
b.) A non-competitive inhibitor
,c.) An allosteric inhibitor
d.) A competitive inhibitor - ✔✔A competitive inhibitor (D)
✔✔An enzyme is participating in a general acid-base catalysis reaction with an optimal
reaction pH of 6.0. If acid is added to the environment reducing the pH to 3, what is the
likely impact to the rate of the reaction?
a.) The rate is likely to decrease as the pH is out of optimal catalytic range.
b.) The rate is likely to increase as the proton concentration has decreased.
c.) The rate is likely to increase as the pH is within the optimal catalytic range.
d.) The rate is likely to remain consistent as this change in the environment will not
affect the kinetics. - ✔✔The rate is likely to decrease as the pH is out of optimal catalytic
range (A)
✔✔An example of enzyme activation by cleavage is best illustrated by which of the
following?
a.) Activation of chymotrypsinogen to chymotrypsin
b.) Phosphorylation of muscle glycogen phosphorylase
c.) Cortisol binding an intracellular receptor
d.) Activation of adenylyl cyclase to generate cAMP - ✔✔Activation of
chymotrypsinogen to chymotrypsin (A)
✔✔The association of DNA and histones can be modified by histone acetylation. A
decrease in histone acetylation will have which of the following impacts on the
association of DNA and histones?
a.) Increase DNA: histone association
b.) Decrease DNA: histone association
c.) Have no impact on the association of DNA and histones - ✔✔Increase DNA: histone
association (A)
✔✔Which of the following is an example of enzyme regulation through covalent
modification?
, a.) Binding of GTP to a monomeric G-protein
b.) Phosphorylation of muscle glycogen phosphorylase
c.) Digestion of misfiled proteins by lysosomes
d.) Cleavage of chymotrypsinogen to chymotrypsin - ✔✔Phosphorylation of muscle
glycogen phosphorylase (B)
✔✔Domains are common structural elements that retain a particular function within a
protein. What is an example of a protein domain? - ✔✔An arrangement of beta-strands
connected by alpha-helices (BaBaB)
✔✔What is the best description of the structure of heme? - ✔✔A planar porphyrin ring
that binds iron
✔✔What type of protein is likely to have a quaternary structure? - ✔✔A multimeric
protein that contains multiple peptide chains
✔✔What is the correct and complete electron transfer pathway for oxidative
phosphorylation? - ✔✔NADH --> complex I --> CoQ --> Complex III --> cyt c -->
complex IV
✔✔If a mutation is made within the active site of an enzyme resulting in a decrease Km,
what is true with respect to enzyme kinetics? - ✔✔The enzyme will require a lower
substrate concentration to reach 1/2 V-max
✔✔What amino acid would not be commonly found in the middle of an alpha-helical
domain? - ✔✔Proline
✔✔Children with cystinosis have growth delay and both renal and ocular issues due to
accumulation of cysteine in cellular lysosomes. The defect involves a specific lysosomal
membrane receptor that facilitates cystine removal from the cell, and an effective
therapy has been administration of a drug with a similar structure to cystine. The
therapy reflects the general principle that competitive inhibitors typically resemble what?
- ✔✔Substrates or ligands that bind to the active site
✔✔Chymotrypsin is a protease that cleaves peptide bonds. It is characterized as which
of the following classes of enzymes?
a.) Oxidoreductase
b.) Transferase
AND ANSWERS GUARANTEE A+
✔✔Heat can be generated by brown adipose tissue in hibernating mammals. Which of
the following is most likely the mechanism by which this occurs?
a.) Increased ATP production by ATP synthase
b.) Expression of a protein that uncouples the ETC
c.) An increased pH gradient across the inner mitochondrial membrane
d.) A decrease in oxygen consumption - ✔✔Expression of a protein that uncouples the
ETC (B)
✔✔Allosteric activators of hemoglobin will increase binding through what mechanism? -
✔✔Binding the protein, and keeping it in the "R" conformation
✔✔An enzyme has a mutation within the substate binding site that reduces the binding
of the coenzyme needed for covalent catalysis. What is likely to result as a
consequence of this mutation? - ✔✔The enzyme will not be able to form the transition
state complex
✔✔How do most enzymes reduce activation energy needed to move a reaction
forward? - ✔✔Providing an active site most complimentary to the transition state
✔✔Under which energy conditions, AMP will bind to phosphofructokinase 1 (PFK1) and
glycogen phosphorylase at site unique of the active site. This enhances the activity of
these enzymes. This is an example of which of the following types of enzyme
regulation?
a.) Allosteric activation
b.) Allosteric inhibition
c.) Competitive inhibition
d.) Covalent modification - ✔✔Allosteric activation (A)
✔✔Which of the following best describes an enzyme inhibitor that increases the Km, but
does not change the V-max?
a.) Inhibition by covalent modification
b.) A non-competitive inhibitor
,c.) An allosteric inhibitor
d.) A competitive inhibitor - ✔✔A competitive inhibitor (D)
✔✔An enzyme is participating in a general acid-base catalysis reaction with an optimal
reaction pH of 6.0. If acid is added to the environment reducing the pH to 3, what is the
likely impact to the rate of the reaction?
a.) The rate is likely to decrease as the pH is out of optimal catalytic range.
b.) The rate is likely to increase as the proton concentration has decreased.
c.) The rate is likely to increase as the pH is within the optimal catalytic range.
d.) The rate is likely to remain consistent as this change in the environment will not
affect the kinetics. - ✔✔The rate is likely to decrease as the pH is out of optimal catalytic
range (A)
✔✔An example of enzyme activation by cleavage is best illustrated by which of the
following?
a.) Activation of chymotrypsinogen to chymotrypsin
b.) Phosphorylation of muscle glycogen phosphorylase
c.) Cortisol binding an intracellular receptor
d.) Activation of adenylyl cyclase to generate cAMP - ✔✔Activation of
chymotrypsinogen to chymotrypsin (A)
✔✔The association of DNA and histones can be modified by histone acetylation. A
decrease in histone acetylation will have which of the following impacts on the
association of DNA and histones?
a.) Increase DNA: histone association
b.) Decrease DNA: histone association
c.) Have no impact on the association of DNA and histones - ✔✔Increase DNA: histone
association (A)
✔✔Which of the following is an example of enzyme regulation through covalent
modification?
, a.) Binding of GTP to a monomeric G-protein
b.) Phosphorylation of muscle glycogen phosphorylase
c.) Digestion of misfiled proteins by lysosomes
d.) Cleavage of chymotrypsinogen to chymotrypsin - ✔✔Phosphorylation of muscle
glycogen phosphorylase (B)
✔✔Domains are common structural elements that retain a particular function within a
protein. What is an example of a protein domain? - ✔✔An arrangement of beta-strands
connected by alpha-helices (BaBaB)
✔✔What is the best description of the structure of heme? - ✔✔A planar porphyrin ring
that binds iron
✔✔What type of protein is likely to have a quaternary structure? - ✔✔A multimeric
protein that contains multiple peptide chains
✔✔What is the correct and complete electron transfer pathway for oxidative
phosphorylation? - ✔✔NADH --> complex I --> CoQ --> Complex III --> cyt c -->
complex IV
✔✔If a mutation is made within the active site of an enzyme resulting in a decrease Km,
what is true with respect to enzyme kinetics? - ✔✔The enzyme will require a lower
substrate concentration to reach 1/2 V-max
✔✔What amino acid would not be commonly found in the middle of an alpha-helical
domain? - ✔✔Proline
✔✔Children with cystinosis have growth delay and both renal and ocular issues due to
accumulation of cysteine in cellular lysosomes. The defect involves a specific lysosomal
membrane receptor that facilitates cystine removal from the cell, and an effective
therapy has been administration of a drug with a similar structure to cystine. The
therapy reflects the general principle that competitive inhibitors typically resemble what?
- ✔✔Substrates or ligands that bind to the active site
✔✔Chymotrypsin is a protease that cleaves peptide bonds. It is characterized as which
of the following classes of enzymes?
a.) Oxidoreductase
b.) Transferase
