Biochemistry Midterm (Units 1 & 2) | Complete
Questions And Answers Rated A+
Troponin ✅A 55-year-old male is brought to the emergency department with a chief
concern 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?
- Lipase
- Lactate dehydrogenase
- Amylase
- Troponin
An arrangement of β-strands connected by α-helices (βαβαβ) ✅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 single α-helix
- A prosthetic group - such as heme
- An arrangement of β-strands connected by α-helices (βαβαβ)
- Irregular coils and loops
Monomeric, tetrameric ✅Myoglobin is a _____ protein. Hemoglobin is a _____ protein.
- Monomeric, tetrameric
- Monomeric, monomeric
- Tetrameric, tetrameric
- Tetrameric, monomeric
Amylase ✅A 22-year old female presents to the emergency room 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. Elevation of which of the following serum enzymes would be consistent with this
diagnosis?
- Amylase
- Troponin
- Creatine kinase
- Lactate dehydrogenase
NADH ✅Which of the following cofactors or coenzymes would not typically participate
in an activation transfer reaction?
- Pyridoxal phosphate (PLP)
- Thiamine pyrophosphate
- Coenzyme A
,- NADH
- Biotin
Binding the enzyme, and keeping it in the "T" conformation ✅Allosteric inhibitors of
hemoglobin will decrease enzyme activity (oxygen binding) through which of the
following mechanisms?
- Binding the enzyme, and keeping it in the "T" conformation
- Binding the enzyme, and keeping it in the "R" conformation
- Binding the enzyme and enhancing Vmax
- Binding the enzyme in "T" conformation and displacing an activator
Secondary structure of the protein ✅An α-helical arrangement of amino acids is
considered to be part of what level of protein structure?
- Secondary structure of the protein
- Tertiary structure of the protein
- Quaternary structure of the protein
- Primary structure of the protein
Valine ✅Covalent catalysis is used by many enzymes to cleave peptide bonds. Which
of the following amino acids would not facilitate this type of catalysis? (Think of the
structure of the R-group of these amino acids)
- Histidine
- Valine
- Cysteine
- Serine
Water ✅Phosphorylation by a kinase requires each of the following except:
- ATP
- Threonine
- Mg2+
- Water
- Serine
Noncompetitive inhibitor ✅An unknown compound is added to a reaction. Overall, the
Vmax of the reaction is decreased but the Km of the enzyme involved is unchanged.
This compound is best defined as which of the following?
- Noncompetitive inhibitor
- Substrate
- Competitive inhibitor
- Cofactor
,The blue line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
✅In the image, the red line indicates enzyme kinetics with no inhibitor present. Based
on this information, which of the following is true?
- The blue line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
- The green line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
- More information is needed regarding the addition of an inhibitor.
- The blue line shows enzyme kinetics with the addition of a competitive inhibitor.
ATP ✅Dephosphorylation by a phosphatase requires each of the following except:
- ATP
- Water
- Mg2+
Decrease DNA:histone association ✅The association of DNA and histones can be
modified by histone acetylation. An increase in histone acetylation will have which of the
following impacts on the association of DNA and histones?
- Increase DNA:histone association
- Decrease DNA:histone association
- Have no impact on the association of DNA and histones
The enzyme will require a higher substrate concentration to reach 1/2 Vmax ✅If a
mutation is made within the active site of an enzyme resulting in an increase in Km,
which of the following will be true with respect to the enzyme kinetics?
- The concentration of substrate needed to reach 1/2 Vmax will not change
- The Vmax of the reaction will increase
- The enzyme will require a lower substrate concentration to reach 1/2 Vmax
- The enzyme will require a higher substrate concentration to reach 1/2 Vmax
Increased ✅During competitive inhibition, Km is _________ .
- Increased
- Decreased
- Unchanged
- Unsaturated
A competitive inhibitor ✅Which of the following best describes an enzyme inhibitor that
increases the Km but does not change the Vmax?
- A competitive inhibitor
- An allosteric inhibitor
- A noncompetitive inhibitor
- Inhibition by covalent modification
, -4 ✅Given the following enzyme pathway, A → B → C → D
The ΔG0' for each of the individual reactions is as follows: A → B is -10; B → C is +5; C
→ D is +1
Using this information, calculate the ΔG0' for the complete process of A → D
- +5
- +2
-0
- -1
- -4
Complex I (NADH Q-oxidoreductase) ✅A 19-year old male is being evaluated for
muscle weakness. Evaluation of a muscle biopsy revealed normal rates of succinate
oxidation but very low rates of pyruvate oxidation. Further testing determined normal
levels of enzymatic activity in both malate dehydrogenase and pyruvate
dehydrogenase. Based on this data, the patient may have a mutation in a gene
encoding for which mitochondrial protein?
- Complex I (NADH Q-oxidoreductase)
- Complex II (Succinate Q-reductase)
- Complex III (Q-cyt c oxidoreductase)
- Complex IV (Cytochrome oxidase)
- Complex V (ATP synthase)
-3 ✅A series of reactions have the following ΔG.
A + B → C ΔG = -1
C + D → E ΔG = +3
E + F → G ΔG = -5
The overall ΔG for this series of reactions is determined to be which of the following
values?
- -6
- +2
- +3
- -3
Entropy ✅The extent of disorder or randomness of a system is measured by
calculating _______ .
- Enthalpy
- Entropy
- Gibbs Free Energy
Increases ✅If a reaction absorbs heat from the surroundings, enthalpy ______ .
Questions And Answers Rated A+
Troponin ✅A 55-year-old male is brought to the emergency department with a chief
concern 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?
- Lipase
- Lactate dehydrogenase
- Amylase
- Troponin
An arrangement of β-strands connected by α-helices (βαβαβ) ✅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 single α-helix
- A prosthetic group - such as heme
- An arrangement of β-strands connected by α-helices (βαβαβ)
- Irregular coils and loops
Monomeric, tetrameric ✅Myoglobin is a _____ protein. Hemoglobin is a _____ protein.
- Monomeric, tetrameric
- Monomeric, monomeric
- Tetrameric, tetrameric
- Tetrameric, monomeric
Amylase ✅A 22-year old female presents to the emergency room 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. Elevation of which of the following serum enzymes would be consistent with this
diagnosis?
- Amylase
- Troponin
- Creatine kinase
- Lactate dehydrogenase
NADH ✅Which of the following cofactors or coenzymes would not typically participate
in an activation transfer reaction?
- Pyridoxal phosphate (PLP)
- Thiamine pyrophosphate
- Coenzyme A
,- NADH
- Biotin
Binding the enzyme, and keeping it in the "T" conformation ✅Allosteric inhibitors of
hemoglobin will decrease enzyme activity (oxygen binding) through which of the
following mechanisms?
- Binding the enzyme, and keeping it in the "T" conformation
- Binding the enzyme, and keeping it in the "R" conformation
- Binding the enzyme and enhancing Vmax
- Binding the enzyme in "T" conformation and displacing an activator
Secondary structure of the protein ✅An α-helical arrangement of amino acids is
considered to be part of what level of protein structure?
- Secondary structure of the protein
- Tertiary structure of the protein
- Quaternary structure of the protein
- Primary structure of the protein
Valine ✅Covalent catalysis is used by many enzymes to cleave peptide bonds. Which
of the following amino acids would not facilitate this type of catalysis? (Think of the
structure of the R-group of these amino acids)
- Histidine
- Valine
- Cysteine
- Serine
Water ✅Phosphorylation by a kinase requires each of the following except:
- ATP
- Threonine
- Mg2+
- Water
- Serine
Noncompetitive inhibitor ✅An unknown compound is added to a reaction. Overall, the
Vmax of the reaction is decreased but the Km of the enzyme involved is unchanged.
This compound is best defined as which of the following?
- Noncompetitive inhibitor
- Substrate
- Competitive inhibitor
- Cofactor
,The blue line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
✅In the image, the red line indicates enzyme kinetics with no inhibitor present. Based
on this information, which of the following is true?
- The blue line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
- The green line shows enzyme kinetics with the addition of a noncompetitive inhibitor.
- More information is needed regarding the addition of an inhibitor.
- The blue line shows enzyme kinetics with the addition of a competitive inhibitor.
ATP ✅Dephosphorylation by a phosphatase requires each of the following except:
- ATP
- Water
- Mg2+
Decrease DNA:histone association ✅The association of DNA and histones can be
modified by histone acetylation. An increase in histone acetylation will have which of the
following impacts on the association of DNA and histones?
- Increase DNA:histone association
- Decrease DNA:histone association
- Have no impact on the association of DNA and histones
The enzyme will require a higher substrate concentration to reach 1/2 Vmax ✅If a
mutation is made within the active site of an enzyme resulting in an increase in Km,
which of the following will be true with respect to the enzyme kinetics?
- The concentration of substrate needed to reach 1/2 Vmax will not change
- The Vmax of the reaction will increase
- The enzyme will require a lower substrate concentration to reach 1/2 Vmax
- The enzyme will require a higher substrate concentration to reach 1/2 Vmax
Increased ✅During competitive inhibition, Km is _________ .
- Increased
- Decreased
- Unchanged
- Unsaturated
A competitive inhibitor ✅Which of the following best describes an enzyme inhibitor that
increases the Km but does not change the Vmax?
- A competitive inhibitor
- An allosteric inhibitor
- A noncompetitive inhibitor
- Inhibition by covalent modification
, -4 ✅Given the following enzyme pathway, A → B → C → D
The ΔG0' for each of the individual reactions is as follows: A → B is -10; B → C is +5; C
→ D is +1
Using this information, calculate the ΔG0' for the complete process of A → D
- +5
- +2
-0
- -1
- -4
Complex I (NADH Q-oxidoreductase) ✅A 19-year old male is being evaluated for
muscle weakness. Evaluation of a muscle biopsy revealed normal rates of succinate
oxidation but very low rates of pyruvate oxidation. Further testing determined normal
levels of enzymatic activity in both malate dehydrogenase and pyruvate
dehydrogenase. Based on this data, the patient may have a mutation in a gene
encoding for which mitochondrial protein?
- Complex I (NADH Q-oxidoreductase)
- Complex II (Succinate Q-reductase)
- Complex III (Q-cyt c oxidoreductase)
- Complex IV (Cytochrome oxidase)
- Complex V (ATP synthase)
-3 ✅A series of reactions have the following ΔG.
A + B → C ΔG = -1
C + D → E ΔG = +3
E + F → G ΔG = -5
The overall ΔG for this series of reactions is determined to be which of the following
values?
- -6
- +2
- +3
- -3
Entropy ✅The extent of disorder or randomness of a system is measured by
calculating _______ .
- Enthalpy
- Entropy
- Gibbs Free Energy
Increases ✅If a reaction absorbs heat from the surroundings, enthalpy ______ .
