UNE Medical Biochemistry Unit 1 ,2,3& 4 Combined
Test With Questions And Answers Rated A+
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)
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
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
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
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
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
Which of the following best describes tertiary structure?
a) interactions between differing subunits of a protein
b) interactions between α-helixes and β-pleated sheets to form a domain
c) interactions between amino acids 4 residues away from each other
d) interactions between single amino acids adjacent to one another ✅interactions
between α-helixes and β-pleated sheets to form a domain
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 ✅prosthetic group
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 ✅substrates or ligands that bind the active site
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 ✅covalent modification
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
c) digestion of misfolded proteins by lysosomes
d) cleavage of chymotrypsinogen to chymotrypsin ✅phosphorylation of muscle
glycogen phosphorylase
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen
phosphorylase. This is an example of which of the follow types of enzyme regulation?
a) competitive inhibition
b) covalent modification
c) allosteric inhibition
d) allosteric activation ✅allosteric activation
The following represents a series of reactions. As levels of B increase, this will decrease
the conversion of S3 to B. Which of the following best describes this type of regulation
in a biosynthetic pathway?
a) feedback inhibition
b) feedforward activation
c) covalent regulation
d) inducible regulation ✅feedback inhibition
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
assocation of DNA and histones?
a) increase DNA:histone association
b) decrease DNA:histone association
Test With Questions And Answers Rated A+
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)
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
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
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
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
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
Which of the following best describes tertiary structure?
a) interactions between differing subunits of a protein
b) interactions between α-helixes and β-pleated sheets to form a domain
c) interactions between amino acids 4 residues away from each other
d) interactions between single amino acids adjacent to one another ✅interactions
between α-helixes and β-pleated sheets to form a domain
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 ✅prosthetic group
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 ✅substrates or ligands that bind the active site
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 ✅covalent modification
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
c) digestion of misfolded proteins by lysosomes
d) cleavage of chymotrypsinogen to chymotrypsin ✅phosphorylation of muscle
glycogen phosphorylase
Under low energy conditions, AMP will bind to phosphofructokinase I and glycogen
phosphorylase. This is an example of which of the follow types of enzyme regulation?
a) competitive inhibition
b) covalent modification
c) allosteric inhibition
d) allosteric activation ✅allosteric activation
The following represents a series of reactions. As levels of B increase, this will decrease
the conversion of S3 to B. Which of the following best describes this type of regulation
in a biosynthetic pathway?
a) feedback inhibition
b) feedforward activation
c) covalent regulation
d) inducible regulation ✅feedback inhibition
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
assocation of DNA and histones?
a) increase DNA:histone association
b) decrease DNA:histone association
