UNE MEDICAL BIOCHEMISTRY UNIT 1 STUDY
GUIDE 2026 EXAM QUESTIONS ANSWERS
VERIFIED GRADED A+
◉ In the image below the blue line indicates enzyme kinetics with
no inhibitor present. Based on this information which of the
following is true?
Answer: The green line shows enzyme kinetics with the addition of a
noncompetitive inhibitor
◉ Hemoglobin bound to heme is termed a holoprotein. The heme is
required for oxygen binding and is defined as which of the
following?
a) apoprotein
b) holoprotein
c) heteroprotein
d) prosthetic group
Answer: prosthetic group
◉ 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?
,Answer: Increase DNA: histone association
◉ Children with cystinosis have growth delay and renal issues to to
accumulation of cysteine in cellular lysosomes. The defect involves a
specific lysosomal membrane receptor that facilitates cysteine
removal from the cell. An effective therapy involves administration
of a drug with a similar structure to cysteine. This therapy reflects
the general principle that competitive inhibitors typically resemble
the structure of which of the following?
a) substrates or ligands that bind the active site
b) enzyme or receptor protein
c) enzyme reaction products
d) the cofactor
Answer: substrates or ligands that bind the active site
◉ A 22-year old female presents to the emergency department with
acute abdominal pain. She indicates the pain came on rapidly in her
mid-abdominal region. Laboratory tests illustrate elevated levels of
amylase. This result would indicate a dysfunction in which of the
following organs?
a) Pancreas
b) Heart
c) Liver
,d) Muscle
Answer: a
◉ An enzyme inhibitor that increases the Km but does not change
the Vmax is classified as:
Answer: a competitive inhibitor
Explanation: A noncompetitive inhibitor will characteristically
increase the Vmax but have no effect on the Km as it does not
interfere with substrate binding. Covalent modifications such as
phosphorylation will change enzyme activity but in a manner such
that enzyme is either active or inactive rather than impacting
kinetics. An allosteric inhibitor is similar to a noncomepetitive
inhibitor such that its presence makes it more difficult for the
substrate to bind; in this case it is difficult for the subunits to be
converted to the most active confirmation and the presence of the
inhibitor usually increases Km and decreases Vmax.
◉ 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. An effective therapy has
been administration of a drug with a similar structure to cystine.
This therapy reflects the general principle that competitive
inhibitors typically resemble the structure of which of the following?
Answer: Substrates or ligands that bind the active site
, ◉ Use the figure below to compare the activities of glucokinase and
hexokinase. Based on this information, which of the following is a
true statement?
Answer: Glucokinase has a higher Km than hexokinase.
◉ A new enzyme is discovered that increases in activity when it is
phosphorylated on an exposed tyrosine. Phosphorylation of this
amino acid is classified as which of the following?
a) feedback inhibition
b) transcriptional activation
c) covalent modification
d) increased protein ubiquitination
Answer: covalent modification
◉ All of the following are considered coenzymes except:
Answer: Heme
Heme is not considered a coenzyme. It is a prosthetic group within
hemoglobin that binds iron. The heme ring itself is not part of
oxygen binding.
GUIDE 2026 EXAM QUESTIONS ANSWERS
VERIFIED GRADED A+
◉ In the image below the blue line indicates enzyme kinetics with
no inhibitor present. Based on this information which of the
following is true?
Answer: The green line shows enzyme kinetics with the addition of a
noncompetitive inhibitor
◉ Hemoglobin bound to heme is termed a holoprotein. The heme is
required for oxygen binding and is defined as which of the
following?
a) apoprotein
b) holoprotein
c) heteroprotein
d) prosthetic group
Answer: prosthetic group
◉ 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?
,Answer: Increase DNA: histone association
◉ Children with cystinosis have growth delay and renal issues to to
accumulation of cysteine in cellular lysosomes. The defect involves a
specific lysosomal membrane receptor that facilitates cysteine
removal from the cell. An effective therapy involves administration
of a drug with a similar structure to cysteine. This therapy reflects
the general principle that competitive inhibitors typically resemble
the structure of which of the following?
a) substrates or ligands that bind the active site
b) enzyme or receptor protein
c) enzyme reaction products
d) the cofactor
Answer: substrates or ligands that bind the active site
◉ A 22-year old female presents to the emergency department with
acute abdominal pain. She indicates the pain came on rapidly in her
mid-abdominal region. Laboratory tests illustrate elevated levels of
amylase. This result would indicate a dysfunction in which of the
following organs?
a) Pancreas
b) Heart
c) Liver
,d) Muscle
Answer: a
◉ An enzyme inhibitor that increases the Km but does not change
the Vmax is classified as:
Answer: a competitive inhibitor
Explanation: A noncompetitive inhibitor will characteristically
increase the Vmax but have no effect on the Km as it does not
interfere with substrate binding. Covalent modifications such as
phosphorylation will change enzyme activity but in a manner such
that enzyme is either active or inactive rather than impacting
kinetics. An allosteric inhibitor is similar to a noncomepetitive
inhibitor such that its presence makes it more difficult for the
substrate to bind; in this case it is difficult for the subunits to be
converted to the most active confirmation and the presence of the
inhibitor usually increases Km and decreases Vmax.
◉ 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. An effective therapy has
been administration of a drug with a similar structure to cystine.
This therapy reflects the general principle that competitive
inhibitors typically resemble the structure of which of the following?
Answer: Substrates or ligands that bind the active site
, ◉ Use the figure below to compare the activities of glucokinase and
hexokinase. Based on this information, which of the following is a
true statement?
Answer: Glucokinase has a higher Km than hexokinase.
◉ A new enzyme is discovered that increases in activity when it is
phosphorylated on an exposed tyrosine. Phosphorylation of this
amino acid is classified as which of the following?
a) feedback inhibition
b) transcriptional activation
c) covalent modification
d) increased protein ubiquitination
Answer: covalent modification
◉ All of the following are considered coenzymes except:
Answer: Heme
Heme is not considered a coenzyme. It is a prosthetic group within
hemoglobin that binds iron. The heme ring itself is not part of
oxygen binding.
