BCH 403 – CUMULATIVE TEST
QUESTIONS WITH ALL CORRECT
ANSWERS
Which one of the following statements regarding glucose oxidation is correct?
A. All 6 carbons from glucose are oxidized to CO2 during the TCA cycle
B. Only 2 of the carbons from glucose are oxidized to CO2, and this occurs during the
TCA cycle.
C. Only 4 of the carbons from glucose are oxidized to CO2, and this occurs during the
TCA cycle
D. 2 carbons are oxidized to CO2 during glycolysis, while 4 carbons are oxidized to
CO2 during the TCA cycle
E. 2 carbons are oxidized to CO2 by the pyruvate dehydrogenase complex, while 4
carbons are oxidized to CO2 during the TCA cycle - Answer-E. 2 carbons are oxidized
to CO2 by the pyruvate dehydrogenase complex, while 4 carbons are oxidized to CO2
during the TCA cycle
Which one of the following TCA cycle enzymes is irreversible and regulated?
A. Citrate synthase
B. Isocitrate dehydrogenase
C. Succinate dehydrogenase
D. α-ketoglutarate dehydrogenase
E. Aconitase - Answer-A. Citrate synthase
Which of the following statements is correct regarding the regulation of pyruvate
dehydrogenase complex?
A. Acetyl-CoA inhibits activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
B. Acetyl-CoA increases activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
C. Acetyl-CoA inhibits activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) phosphatase
D. Acetyl-CoA increases activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
E. Despite being a product of pyruvate dehydrogenase (PDH), acetyl-CoA does not
regulate the activity of PDH - Answer-A. Acetyl-CoA inhibits activity of pyruvate
dehydrogenase by activating pyruvate dehydrogenase (PDH) kinase
How many protons are pumped across Complex IV per reducing equivalent?
A. 1
B. 2
C. 3
,D. 4
E. 5 - Answer-B. 2
What is the correct order of electron transfer through the respiratory chain (Assume
NADH as the starting point)?
A. Complex I → Complex II → Complex III → Complex IV → Complex V → O2
B. Complex I → Complex II → Coenzyme Q → Complex III → Complex IV → O2
C. Complex I → Coenzyme Q → Complex III → Cytochrome c → Complex IV → O2
D. Complex I → Coenzyme Q → Complex III → Complex IV → Cytochrome c → O2
E. Complex II → Coenzyme Q → Complex III → Cytochrome c → Complex IV → O2 -
Answer-C. Complex I → Coenzyme Q → Complex III → Cytochrome c → Complex IV
→ O2
Pumping of protons across the inner membrane via Complex V (or ATP synthase) into
the mitochondrial matrix requires:
A. Both a- and c-subunits
B. a-subunit
C. c-subunit
D. α-subunit
E. Both α- and β-subunits - Answer-A. Both a- and c-subunits
Adenine nucleotide translocase:
A. Transports ATP out of the mitochondria while transporting ADP into the mitochondria
B. Transports inorganic phosphate (Pi) into the mitochondria at the cost of two H+
C. Transports inorganic phosphate (Pi) out of the mitochondria matrix
D. Transports H+ into the mitochondria matrix
E. Transports electrons from cytosolic NADH into the mitochondria - Answer-A.
Transports ATP out of the mitochondria while transporting ADP into the mitochondria
Which one of the following statements is correct?
A. All 5 respiratory complexes pump protons
B. Only complex V pumps protons
C. Complex IV pumps more protons across the mitochondrial membrane than Complex
I
D. Complex II is part of the TCA cycle
E. Complex III is only involved in the transport of electrons from NADH - Answer-D.
Complex II is part of the TCA cycle
T/F: Triacylglycerol is an energy storage molecule. - Answer-True
T/F: Both adipose glyceride lipase and hormone sensitive lipase are regulated enzymes
in fat mobilization (also called lipid mobilization). - Answer-True
T/F: Skeletal muscles cannot utilize ketone bodies as fuel because they lack the
enzymes needed to degrade ketone bodies to acetyl-CoA. - Answer-False
, T/F: Glyceroneogenesis requires 2 oxidation steps. - Answer-False
T/F: Cholesterol consists of 27 carbons, all of which originate from 18 acetyl-CoA. -
Answer-True
T/F: Intracellular turnover of proteins can only be accomplished by proteasome. -
Answer-False
T/F: mTOR signals a high energy state of a cell. - Answer-True
T/F: Type I Diabetes is caused by the inability of the pancreas to synthesize insulin. -
Answer-True
T/F: During starvation, skeletal muscles will export alanine into the bloodstream where it
is picked up by the liver and used as a precursor for gluconeogenesis. - Answer-True
T/F: Only the adipose is capable of triacylglycerol biosynthesis. - Answer-False
The small intestine packages dietary (or exogenous) lipids into the:
A. Chylomicron
B. Very low density lipoprotein
C. Low density lipoprotein
D. High density lipoprotein
E. Intermediate density lipoprotein - Answer-A. Chylomicron
Which one of the following lipases is capable of cleaving all 3 fatty acids off of
triacylglycerol?
A. Salivary lipase
B. Pancreatic lipase
C. Hormone sensitive lipase
D. Lipoprotein lipase
E. Adipose triglyceride lipase - Answer-D. Lipoprotein lipase
T/F: The thermodynamics of a biochemical reaction can be driven by either favorable
changes in enthalpy or favorable changes in entropy, but not by both. - Answer-False
T/F: Hydrogen bonds are weak electrostatic interactions that are made possible by the
presence of partial charges on H-bond donors and acceptors. - Answer-True
T/F: Carbonic acid has a pKa of 6.37; acetic acid has a pKa of 4.76; therefore, carbonic
acid is the stronger acid. - Answer-False
T/F: Small proteins elute earliest in a gel filtration column, but travel fastest on SDS-
PAGE. - Answer-False
QUESTIONS WITH ALL CORRECT
ANSWERS
Which one of the following statements regarding glucose oxidation is correct?
A. All 6 carbons from glucose are oxidized to CO2 during the TCA cycle
B. Only 2 of the carbons from glucose are oxidized to CO2, and this occurs during the
TCA cycle.
C. Only 4 of the carbons from glucose are oxidized to CO2, and this occurs during the
TCA cycle
D. 2 carbons are oxidized to CO2 during glycolysis, while 4 carbons are oxidized to
CO2 during the TCA cycle
E. 2 carbons are oxidized to CO2 by the pyruvate dehydrogenase complex, while 4
carbons are oxidized to CO2 during the TCA cycle - Answer-E. 2 carbons are oxidized
to CO2 by the pyruvate dehydrogenase complex, while 4 carbons are oxidized to CO2
during the TCA cycle
Which one of the following TCA cycle enzymes is irreversible and regulated?
A. Citrate synthase
B. Isocitrate dehydrogenase
C. Succinate dehydrogenase
D. α-ketoglutarate dehydrogenase
E. Aconitase - Answer-A. Citrate synthase
Which of the following statements is correct regarding the regulation of pyruvate
dehydrogenase complex?
A. Acetyl-CoA inhibits activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
B. Acetyl-CoA increases activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
C. Acetyl-CoA inhibits activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) phosphatase
D. Acetyl-CoA increases activity of pyruvate dehydrogenase by activating pyruvate
dehydrogenase (PDH) kinase
E. Despite being a product of pyruvate dehydrogenase (PDH), acetyl-CoA does not
regulate the activity of PDH - Answer-A. Acetyl-CoA inhibits activity of pyruvate
dehydrogenase by activating pyruvate dehydrogenase (PDH) kinase
How many protons are pumped across Complex IV per reducing equivalent?
A. 1
B. 2
C. 3
,D. 4
E. 5 - Answer-B. 2
What is the correct order of electron transfer through the respiratory chain (Assume
NADH as the starting point)?
A. Complex I → Complex II → Complex III → Complex IV → Complex V → O2
B. Complex I → Complex II → Coenzyme Q → Complex III → Complex IV → O2
C. Complex I → Coenzyme Q → Complex III → Cytochrome c → Complex IV → O2
D. Complex I → Coenzyme Q → Complex III → Complex IV → Cytochrome c → O2
E. Complex II → Coenzyme Q → Complex III → Cytochrome c → Complex IV → O2 -
Answer-C. Complex I → Coenzyme Q → Complex III → Cytochrome c → Complex IV
→ O2
Pumping of protons across the inner membrane via Complex V (or ATP synthase) into
the mitochondrial matrix requires:
A. Both a- and c-subunits
B. a-subunit
C. c-subunit
D. α-subunit
E. Both α- and β-subunits - Answer-A. Both a- and c-subunits
Adenine nucleotide translocase:
A. Transports ATP out of the mitochondria while transporting ADP into the mitochondria
B. Transports inorganic phosphate (Pi) into the mitochondria at the cost of two H+
C. Transports inorganic phosphate (Pi) out of the mitochondria matrix
D. Transports H+ into the mitochondria matrix
E. Transports electrons from cytosolic NADH into the mitochondria - Answer-A.
Transports ATP out of the mitochondria while transporting ADP into the mitochondria
Which one of the following statements is correct?
A. All 5 respiratory complexes pump protons
B. Only complex V pumps protons
C. Complex IV pumps more protons across the mitochondrial membrane than Complex
I
D. Complex II is part of the TCA cycle
E. Complex III is only involved in the transport of electrons from NADH - Answer-D.
Complex II is part of the TCA cycle
T/F: Triacylglycerol is an energy storage molecule. - Answer-True
T/F: Both adipose glyceride lipase and hormone sensitive lipase are regulated enzymes
in fat mobilization (also called lipid mobilization). - Answer-True
T/F: Skeletal muscles cannot utilize ketone bodies as fuel because they lack the
enzymes needed to degrade ketone bodies to acetyl-CoA. - Answer-False
, T/F: Glyceroneogenesis requires 2 oxidation steps. - Answer-False
T/F: Cholesterol consists of 27 carbons, all of which originate from 18 acetyl-CoA. -
Answer-True
T/F: Intracellular turnover of proteins can only be accomplished by proteasome. -
Answer-False
T/F: mTOR signals a high energy state of a cell. - Answer-True
T/F: Type I Diabetes is caused by the inability of the pancreas to synthesize insulin. -
Answer-True
T/F: During starvation, skeletal muscles will export alanine into the bloodstream where it
is picked up by the liver and used as a precursor for gluconeogenesis. - Answer-True
T/F: Only the adipose is capable of triacylglycerol biosynthesis. - Answer-False
The small intestine packages dietary (or exogenous) lipids into the:
A. Chylomicron
B. Very low density lipoprotein
C. Low density lipoprotein
D. High density lipoprotein
E. Intermediate density lipoprotein - Answer-A. Chylomicron
Which one of the following lipases is capable of cleaving all 3 fatty acids off of
triacylglycerol?
A. Salivary lipase
B. Pancreatic lipase
C. Hormone sensitive lipase
D. Lipoprotein lipase
E. Adipose triglyceride lipase - Answer-D. Lipoprotein lipase
T/F: The thermodynamics of a biochemical reaction can be driven by either favorable
changes in enthalpy or favorable changes in entropy, but not by both. - Answer-False
T/F: Hydrogen bonds are weak electrostatic interactions that are made possible by the
presence of partial charges on H-bond donors and acceptors. - Answer-True
T/F: Carbonic acid has a pKa of 6.37; acetic acid has a pKa of 4.76; therefore, carbonic
acid is the stronger acid. - Answer-False
T/F: Small proteins elute earliest in a gel filtration column, but travel fastest on SDS-
PAGE. - Answer-False
