UNE Medical Biochemistry Unit 1 Test Questions
And Answers Rated A+
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline.
It is considered a 'helix breaker' and would not be found in an alpha helix; all other
residues are nonpolar hydrophobic and could reside in a transmembrane domain.
Changes in the physiological variables listed below can alter the affinity of hemoglobin
for oxygen. Which of the following will lower the affinity of hemoglobin for oxygen?
a) decrease in protons
b) increase in 2,3 diphosphoglycerate (BPG)
c) increase in pH
d) decrease in CO2 ✅Increase in 2,3 diphosphoglycerate (BPG)
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. She has vomited
several times over the last 4 hours. A diagnosis of acute pancreatitis is made and she is
rushed to surgery. Elevation of which of the following serum enzymes would be
consistent with this diagnosis? ✅Amylase
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Cleavage of fructose 1, 6-bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes? ✅Lyase
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline
Domains are common structural elements that retain a particular function within the
protein. Which of the following is an example of a protein domain?
a) a prosthetic group such as heme
b) irregular coils and loops
c) an arrangement of β-strands connected by α- helixes
d) a single α- helix ✅An arrangement of β-strands connected by α-helixes
α helices and β sheets are primarily stabilized by which of the following interactions?
✅hydrogen bonding
,Hydrogen bonding is the primary stabilizing force in both secondary structures. In alpha
helices the hydrogen bond is between the carbonyl oxygen group from one peptide
bond and that amide hydrogen from a different peptide bond approximately amide 4
resides down in the helix. In beta sheets, the hydrogen bonding is between the carbonyl
oxygen and the amide hydrogen from different peptide strands.
Compare and contrast beta sheets and alpha helical formations. (Figure 7.3 vs. 7.5)
Phosphorylation of an amino acid changes the charge on the residue to: ✅Negative
The addition of a phospho group will add a large negative moiety to the amino acid and
change the functionality of the protein.
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline
A 55-year old man is brought to the emergency room with a chief complaint of chest
pain and tingling in his left arm. Elevation of which of the following enzymes in
circulation would be most indicative of a myocardial infarction? ✅Troponin
A 22-year-old female is diagnosed with acute pancreatitis. Elevation of which of the
following serum enzymes would be consistent with this diagnosis?
a) lactate dehydrogenase
b) amylase
c) troponin
d) creatine kinase ✅amylase
Hemoglobin binds oxygen with a greater affinity in the: ✅R-State --- Hemoglobin binds
oxygen with a greater affinity in the R state. As oxygen binds each subunit, the affinity
for oxygen increases; this is termed cooperative binding.
A 19-year-old boy is diagnosed with Creutzfeldt-Jakob Disease which is caused by the
introduction of an amyloid fold in the disease-causing protein. The introduction of this
fold causes the protein to transition from a primarily α-helical structure to an aggregate
of mostly β-sheets. This change in protein structure (leading to disease) is best
attributed to changes in which of the following? ✅Folding of the secondary structures
α-helices and β-sheets are primarily stabilized by which of the following interactions
✅Hydrogen bonding
Movement of ammonia from an amino acid to an alpha-keto acid involves a family of
enzymes best categorized as:
a) transferases
b) ligases
,c) lyases
d) isomerases ✅transferases
Which of the following proteins is likely to have quaternary structure?
a) a protein that contains both α-helix and β-sheet secondary structures
b) a multimeric protein that contains multiple peptide chains
c) a small protein consisting of a single amino acid chain
d) a large transmemberane protein with seven alpha helical domains ✅a multimeric
protein that contains multiple peptide chains
A decrease in blood pH from 7.0 to 6.0 would be accompanied by which of the following
changes in ion concentration? ✅A 10-fold increase in hydrogen ion concentration-
Explanation: The pH is the negative log of the hydrogen ion concentration, [H+]. At a pH
of 7.0 [H+] is 10-7; and at pH 6.0[H+] is 10-6. The [H+] has changed by a factor of 10-
6/10-7 which is 10. A decrease in 1 pH units is a 10 fold increase in [H+]
Cleavage of fructose 1, 6-bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes? ✅Lyase
A 55-year old man is brought to the emergency room with a chief complaint of chest
pain and tingling in his left arm. Elevation of which of the following enzymes in
circulation would be most indicative of a myocardial infarction? ✅Troponin
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Discriminate between primary, secondary, tertiary, and quaternary protein structure
(Overview Figure 7.1)
Hemoglobin bound to heme is termed a holoprotein. The heme or porphyrin ring is
required for oxygen binding and it is defined as which of the following? ✅Prosthetic
group
An enzyme has a mutation within the substrate binding site that reduces the binding of
the coenzyme needed for covalent catalysis. Which of the following is likely to result as
a consequence of this mutation? ✅The enzyme will not be able to form the transition
state complex
Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes?
a) ligase
b) lyase
c) transferase
, d) hydrolase ✅Lyase
Hemoglobin bound to heme is termed a holoprotein. The heme or porphyrin ring is
required for oxygen binding and it is termed a: ✅prosthetic group
Hemoglobin or myoglobin bound to the heme prosthetic group is termed a holoprotein.
Without the heme the protein is termed an apoprotein.
Describe the structural difference between hemoglobin and myoglobin and compare O2
binding properties of hemoglobin and myoglobin (Figure 7.10 and 7.11)
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Allosteric activators of hemoglobin will increase enzyme activity through which of the
following mechanisms? ✅Binding the enzyme, and keeping it in the "R" conformation
Which of the following best describes the structure of heme?
a) a planar porphyrin ring that binds iron
b) a nicotinamide structure that is readily oxidized
c) an n-linked glycosylation
d) a negatively charged phosphate group ✅a planar porphyrin ring that binds iron
Prosthetic groups are complex nonprotein molecules that participate in catalysis by
providing functional groups that form a covalent intermediate between the enzyme and
the substrate. Which of the following is an example of a coenzyme or cofactor that
participates in a covalent catalysis reaction?
a) ATP
b) OH-
c) NADH
d) pyridoxal phosphate ✅pyridoxal phsophate
Domains are common structural elements that retain a particular function within the
protein. Which of the following is an example of a protein domain? ✅An arrangement
of β-strands connected by α-helices (βαβαβ)
An enzyme has a mutation within the substrate binding site that reduces the binding of
the coenzyme needed for covalent catalysis. Which of the following is likely to result as
a consequence of this mutation? ✅The enzyme will not be able to form the transition
state complex
Aspartate is classified as a: ✅charged amino acid
And Answers Rated A+
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline.
It is considered a 'helix breaker' and would not be found in an alpha helix; all other
residues are nonpolar hydrophobic and could reside in a transmembrane domain.
Changes in the physiological variables listed below can alter the affinity of hemoglobin
for oxygen. Which of the following will lower the affinity of hemoglobin for oxygen?
a) decrease in protons
b) increase in 2,3 diphosphoglycerate (BPG)
c) increase in pH
d) decrease in CO2 ✅Increase in 2,3 diphosphoglycerate (BPG)
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. She has vomited
several times over the last 4 hours. A diagnosis of acute pancreatitis is made and she is
rushed to surgery. Elevation of which of the following serum enzymes would be
consistent with this diagnosis? ✅Amylase
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Cleavage of fructose 1, 6-bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes? ✅Lyase
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline
Domains are common structural elements that retain a particular function within the
protein. Which of the following is an example of a protein domain?
a) a prosthetic group such as heme
b) irregular coils and loops
c) an arrangement of β-strands connected by α- helixes
d) a single α- helix ✅An arrangement of β-strands connected by α-helixes
α helices and β sheets are primarily stabilized by which of the following interactions?
✅hydrogen bonding
,Hydrogen bonding is the primary stabilizing force in both secondary structures. In alpha
helices the hydrogen bond is between the carbonyl oxygen group from one peptide
bond and that amide hydrogen from a different peptide bond approximately amide 4
resides down in the helix. In beta sheets, the hydrogen bonding is between the carbonyl
oxygen and the amide hydrogen from different peptide strands.
Compare and contrast beta sheets and alpha helical formations. (Figure 7.3 vs. 7.5)
Phosphorylation of an amino acid changes the charge on the residue to: ✅Negative
The addition of a phospho group will add a large negative moiety to the amino acid and
change the functionality of the protein.
Which of the following amino acid would not be commonly found in the middle of a an α-
helical domain? ✅Proline
A 55-year old man is brought to the emergency room with a chief complaint of chest
pain and tingling in his left arm. Elevation of which of the following enzymes in
circulation would be most indicative of a myocardial infarction? ✅Troponin
A 22-year-old female is diagnosed with acute pancreatitis. Elevation of which of the
following serum enzymes would be consistent with this diagnosis?
a) lactate dehydrogenase
b) amylase
c) troponin
d) creatine kinase ✅amylase
Hemoglobin binds oxygen with a greater affinity in the: ✅R-State --- Hemoglobin binds
oxygen with a greater affinity in the R state. As oxygen binds each subunit, the affinity
for oxygen increases; this is termed cooperative binding.
A 19-year-old boy is diagnosed with Creutzfeldt-Jakob Disease which is caused by the
introduction of an amyloid fold in the disease-causing protein. The introduction of this
fold causes the protein to transition from a primarily α-helical structure to an aggregate
of mostly β-sheets. This change in protein structure (leading to disease) is best
attributed to changes in which of the following? ✅Folding of the secondary structures
α-helices and β-sheets are primarily stabilized by which of the following interactions
✅Hydrogen bonding
Movement of ammonia from an amino acid to an alpha-keto acid involves a family of
enzymes best categorized as:
a) transferases
b) ligases
,c) lyases
d) isomerases ✅transferases
Which of the following proteins is likely to have quaternary structure?
a) a protein that contains both α-helix and β-sheet secondary structures
b) a multimeric protein that contains multiple peptide chains
c) a small protein consisting of a single amino acid chain
d) a large transmemberane protein with seven alpha helical domains ✅a multimeric
protein that contains multiple peptide chains
A decrease in blood pH from 7.0 to 6.0 would be accompanied by which of the following
changes in ion concentration? ✅A 10-fold increase in hydrogen ion concentration-
Explanation: The pH is the negative log of the hydrogen ion concentration, [H+]. At a pH
of 7.0 [H+] is 10-7; and at pH 6.0[H+] is 10-6. The [H+] has changed by a factor of 10-
6/10-7 which is 10. A decrease in 1 pH units is a 10 fold increase in [H+]
Cleavage of fructose 1, 6-bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes? ✅Lyase
A 55-year old man is brought to the emergency room with a chief complaint of chest
pain and tingling in his left arm. Elevation of which of the following enzymes in
circulation would be most indicative of a myocardial infarction? ✅Troponin
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Discriminate between primary, secondary, tertiary, and quaternary protein structure
(Overview Figure 7.1)
Hemoglobin bound to heme is termed a holoprotein. The heme or porphyrin ring is
required for oxygen binding and it is defined as which of the following? ✅Prosthetic
group
An enzyme has a mutation within the substrate binding site that reduces the binding of
the coenzyme needed for covalent catalysis. Which of the following is likely to result as
a consequence of this mutation? ✅The enzyme will not be able to form the transition
state complex
Cleavage of fructose 1, 6 bisphosphate to dihydroxyacetone and glyceraldehyde 3-
phosphate is achieved by what class of enzymes?
a) ligase
b) lyase
c) transferase
, d) hydrolase ✅Lyase
Hemoglobin bound to heme is termed a holoprotein. The heme or porphyrin ring is
required for oxygen binding and it is termed a: ✅prosthetic group
Hemoglobin or myoglobin bound to the heme prosthetic group is termed a holoprotein.
Without the heme the protein is termed an apoprotein.
Describe the structural difference between hemoglobin and myoglobin and compare O2
binding properties of hemoglobin and myoglobin (Figure 7.10 and 7.11)
Which of the following is the best description of primary protein structure? ✅A newly
synthesized strand of amino acids
Allosteric activators of hemoglobin will increase enzyme activity through which of the
following mechanisms? ✅Binding the enzyme, and keeping it in the "R" conformation
Which of the following best describes the structure of heme?
a) a planar porphyrin ring that binds iron
b) a nicotinamide structure that is readily oxidized
c) an n-linked glycosylation
d) a negatively charged phosphate group ✅a planar porphyrin ring that binds iron
Prosthetic groups are complex nonprotein molecules that participate in catalysis by
providing functional groups that form a covalent intermediate between the enzyme and
the substrate. Which of the following is an example of a coenzyme or cofactor that
participates in a covalent catalysis reaction?
a) ATP
b) OH-
c) NADH
d) pyridoxal phosphate ✅pyridoxal phsophate
Domains are common structural elements that retain a particular function within the
protein. Which of the following is an example of a protein domain? ✅An arrangement
of β-strands connected by α-helices (βαβαβ)
An enzyme has a mutation within the substrate binding site that reduces the binding of
the coenzyme needed for covalent catalysis. Which of the following is likely to result as
a consequence of this mutation? ✅The enzyme will not be able to form the transition
state complex
Aspartate is classified as a: ✅charged amino acid
