Biochemistry Practice Questions for Exam 2:
1. Which enzyme is activated by phosphorylation?
A. Phosphofructokinase-2
B. Pyruvate Dehydrogenase
C. Acetyl-CoA Carboxylase
D. HMG-CoA Reductase
E. Reductase Kinase
2.
A
B
C
Which of the above molecules is an epimer of the molecule shown below:
A.
B.
C.
D.
E.
A
B
C
A and C
None of the above
3. How many ATP equivalents are required to make 1 glucose from pyruvate via
gluconeogenesis?
A. 0
B. 2
C. 4
D. 6
E. 8
4. A pathologist examines a patient's blood smear and finds that his RBCs are smaller than
normal and that some of them lack color. Which of the following is the likely cause of these
findings?
A. Pyroxidine deficiency
B. Defective transport of tryptophan in intestine and kidney
C. Folic acid deficiency
D. Defective calmodulin binding to phosphorylase kinase
E. Excessive intake of Vitamin E
5. Which of the following is associated with a defect in Cu-ATPase of the intestine?
A. mental retardation
B. increased levels of copper in the liver
C. decreased ceruloplasmin concentration
D. Kayser-Fleischer ring
E. increased levels of copper in the blood
6. Which of the following is a result of Pyruvate Kinase Deficiency?
A. Microcytic Anemia
B. Decreased levels of 2,3 BPG
C. Decreased affinity for O2 in Hemoglobin
D. Increased production of pyruvate
E. Increased ATP production in erythrocytes
7. During your pediatrics rotation, a young couple brings their 11 month old child in with
complaints that the child has recently had excessive vomiting. Upon examination, the child
appears pallored and is trembling, and the family reports that he has recently appeared more
fatigued than usual. After speaking with the parents, you learn they have recently started
feeding their child with formula. The child has otherwise been completely healthy up to this
point. When reporting to your attending, you tell them you suspect the child has a deficiency in
which enzyme?
A . Fructokinase
B. Phosphofructokinase 2
C. Aldolase B
D. Uridyl Transferase
E. Lactate Dehydrogenase
8. How many ATP equivalents are produced from complete aerobic oxidation of Palmitoyl CoA?
A. 127
B. 129
C. 131
D. 132
E. 133
9. Which of the following is NOT associated with Medium Chain Acyl CoA Dehydrogenase
(MCAD) deficiency?
A. Increased Omega-Oxidation of fatty acids
B. Presence of dicarboxylic acids in bloodsteam
C. Decreased activity of pyruvate carboxylase
D. Increased production of ketone bodies
E. Presence of medium chain acylcarnitines in bloodstream
10. Which of the following is NOT associated with B12 deficiency?
A. Pernicious anemia
B. Myopathic Carnitine deficiency (myopathic CAT deficiency)
C. Megaloblastic anemia
D. Progressive Peripheral Neuropathy
E. Methyl Malonic Acidemia
11. Which fatty acid can be formed by one round of desaturation of Stearate?
A. Linoleate
B. Palmitate
C. Arachidonate
D. alpha-Linolenate
E. Oleate
12. The blood work for one of your patients shows that the patient has a blood glucose
concentration of 4.4mM. Upon physical examination, you find that the patient’s liver is also
enlarged. After further tests you find that the patient is deficient in an enzyme. Which enzyme is
likely deficient in this patient, leading to the symptoms noted above?
A. Glucose-6-Phosphatase
B. Liver Phosphorylase
C. Phosphodiesterase
D. Lysosomal alpha-Glucosidase
E. Phosphorylase Kinase
13. Which of the following individuals should be most concerned about ingesting excess Vitamin
A?
A. An alcoholic
B. A newborn
C. A 5 year old
D. A pregnant woman
E. A homeless person
14. Which of the following is not a potential source of Propionate?
A. Threonine
B. Isoleucine
C.Tyrosine
D. Methionine
E. Valine
15. A patient presents to your clinic with muscle weakness. He appears to have some mental
confusion and a loss of both his sense of reality and his control of body movements, and also
has very wide-set eyes. While checking his vitals you notice that his heart rate is lower than
normal. This specific symptom set is related to a disease that is caused by a genetic defect of
what enzyme?
A. Pyruvate Kinase
B. Transketolase
C. Uridyl Transferase
D. Phosphoglucomutase
E. Lysosomal alpha-1,4-glucosidase
16. A compound that inhibits Porphobilinogen Deaminase (the enzyme that catalyzes the PBG
→ Hydroxymethylbilane reaction) would likely lead to symptoms resembling which of these
diseases?
A. Lead Poisoning
B. Methemoglobemia
C. G6PD Deficiency
D. Hepatic Porphyria
E. Erythropoietic Porphyria
17. De Vivo disease is a rare genetic disorder that is caused by a deficiency of GLUT1,
decreasing the transporter’s functionality. Which of these symptoms would you expect to result
from this defect?
A. Hypoglycemia
B. Neurological problems
C. High CSF Glucose Concentration
D. Hepatomegaly
E. Muscle Weakness
18. Which of the following is not true regarding the action of insulin?
A. It increases Acetyl CoA Carboxylase expression
B. It leads to the dephosphorylation of a number of enzymes
C. It will favor Glycogen synthesis
D. It increases expression of GLUT3
E. It increases the activity of PFK-2
19. Which of the following would be seen in someone who recently ingested Dinitrophenol?
A. Increased respiratory chain electron flow
B. Inhibited F1F0 ATP Synthase
C. Decreased respiratory chain electron flow
D. Lactic Acidosis
E. Hyperglycemia
20. Which of the following would not inhibit blood clotting?
A. EDTA
B. Fluoride
C. Citrate
D. ALA
E. Dicumarol
21. Insulin binding on muscle and adipose tissue releases GLUT4 from vesicles by activating:
A. Fructose 2,6 Bisphosphatase
B. PI-3 Kinase
C. Aldolase Reductase
D. Phosphofructokinase-2
E. Phosphofructokinase-1
22. Which of the following enzymes functions in the mitochondria?
A. PEP carboxykinase
B. ALA Synthase
C. Citrate Lyase
D. Malic Enzyme
E. HMG CoA reductase
23. Which of the following people would be most likely to have high levels of direct bilirubin?
A. A newborn
B. A child with Crigler Najjar Syndrome
C. A person with Choledocholithiasis (gallstone in bile duct)
D. A person with hemolytic anemia
E. A person with Gilbert’s Syndrome
24. The hydrolysis of sucrose gives:
A. galactose and fructose
B. galactose and glucose
C. glucose and fructose
D. fructose and glucose
E. 2 glucoses
25.
A deficiency of the above molecule would lead to which of the following diseases?
A. Pellagra
B. Megaloblastic Anemia
C. Beri- Beri
D. Alopecia
E. No known deficiencies are associated with this molecule