Exam 3

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Exam 3

1. The aconitase enzyme is an important enzyme in Krebs cycle activity which converts citric acid into isocitric acid. Within the aconitase enzyme is a cluster of two elements responsible for proper activation of aconitase activity. This same cluster of elements is also found in succinic acid dehydrogenase, as well as the electron transport chain. What are the two elements that make up this cluster?

1. Copper and sulfur

2. Manganese and iron

3. Cobalt and copper

4. Iron and sulfur

5. None of the above

2. The cristae of the mitochondria are created by infoldings of the outer mitochondrial membrane?

1. True

2. False

3. All the following are functions of mitochondria, except?

1. Calcium regulation

2. Cellular apoptosis

3. Adenosine triphosphate production

4. Maintaining cellular membrane potential

5. All the above are correct

4. The matrix contains approximately two-thirds of the mitochondrion proteins.

1. True

2. False

5. Which structure of the mitochondria contains porins?

1. Matrix

2. Outer mitochondrial membrane

3. Cristae

4. Inner mitochondrial membrane

5. None of the above

6. The mitochondria have a mechanism for producing heat that does not involve ATP production.

1. True

2. False

7. Which nucleotides are associated with deoxyribonucleic acid (DNA)?

1. Adenine

2. Thymine

3. Guanine

4. Cytosine

5. All the above are correct

8. Maternal inheritance linked to mitochondrial disorders involves both the man and woman, but mostly the man.

1. True

2. False

9. Which of the following pairings with regards to mitochondrial disorder symptoms is not correct?

1. Swallowing - dysphagia

2. Myopathy - muscle weakness

3. Ptosis – elevated eye lids

4. A & B

5. None of these

10. The hallmark of mitochondrial disease is the variability of the disease process within the same family or individuals despite similar mutations, which may complicate the diagnosis.

1. True

2. False

11. All the following are correct with regards to mitochondrial disorders, except?

1. The prevalence of mitochondrial diseases is estimated to be about 1 in 5000 across all ages.

2. The clinical manifestations are often complex and can involve all organ systems.

3. The organ with high energy demands, e.g., brain, eyes, liver, muscles, nerves are particularly at risk.

4. Phenotypic expression is highly variable in affected members within or between family members, even across the same disease spectrum.

5. All of the above

12. Mitochondrial disorder refers to primary disorders of mitochondrial metabolism affecting oxidative phosphorylation.

1. True

2. False

13. All the following are correct regarding cardiolipin as a structural component of the inner mitochondrial membrane (IMM), except?

1. Cardiolipin makes up about 20% of the total lipid composition of the IMM.

2. Cardiolipin can be altered in its function by antibodies produced by the immune system.

3. Cardiolipin contains four phospholipid chains as opposed to two seen with other phospholipids.

4. Cardiolipin is chemically involved in maintaining optimal cohesiveness of the electron transport chain complexes.

5. All the above are correct

14. Each ATP molecule is recycled about 1000 times with nearly 70% of the ATP used occurring in the brain and nervous system.

1. True

2. False

15. The outer mitochondrial membrane has a protein to phospholipid ratio of 1:1, but the inner mitochondrial membrane is 3:1.

1. True

2. False

16. This compound which is part of the inner mitochondrial membrane gets released into the intermembrane space triggering apoptosis?

1. Complex I

2. ATP Synthetase

3. Cristae

4. Cytochrome c

5. Iron-sulfur cluster

17. A common problem with certain mitochondrial disorders that affect cellular metabolism is the development of elevated organic acids. Which of the following organic acids, as discussed in module #2, is important and relatively easy to assess through blood testing and/or organic acids testing?

1. Malonic acid

2. 2-hydroxyhippuric acid

3. Lactic acid

4. 4-hydroxyphenylacetic acid

5. None of the above

18. Mitochondrial genes involve sequences for the development of the following electron transport chain (ETC) complexes?

1. II

2. I, II, III

3. I, III, IV, V

4. V Only

5. None of the above

19. What is the innermost aspect of the mitochondria?

1. Inner mitochondrial membrane

2. Cristae

3. Matrix

4. Outer mitochondrial membrane

5. None of the above

20. The endoplasmic reticulum is considered the energy factory of our cells.

1. True

2. False

21. All the following are correct with regards to glycolysis, the production of acetyl-CoA, and enzyme conversion of pyruvate to Acetyl-CoA, except?

1. Glycolysis is the conversion of glucose to pyruvate. This reaction takes place in the cytosol of the cell where one molecule of glucose (6 carbons) is converted into two 3 carbon pyruvates.

2. Pyruvate is taken into the mitochondrial where it gets converted to Acetyl-CoA. The enzyme pyruvate dehydrogenase (PDH) is responsible for this conversion. The PDH requires various nutrients, e.g., B1, B2, B5, magnesium. It is regulated by another pyruvate enzyme called pyruvate dehydrogenase kinase (PDK).

3. The pyruvate dehydrogenase is a complex of different proteins and often referred to as pyruvate dehydrogenase complex (PDC). Increase of PDK inhibits PCD activity.

4. Various cellular compounds limit PDC activity such as Acetyl-CoA, ATP, and NADH.

5. All the above are correct.

22. ATP has no structural similarity to ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) because of the lack of a ribose backbone and phosphate groups.

1. True

2. False

23. Anaerobic metabolism accounts for 5% of the cells ATP production, and the Kreb cycle activity accounts for another 5%. How much does the electron transport chain involved in oxidative phosphorylation provide (approximately)?

1. 10%

2. 2.5%

3. 20%

4. 90%

24. In oncology, the Warburg Effect, is the observation that most cancer cells produce energy through a less efficient or “aerobic glycolysis” by glucose uptake, glycolysis, and lactic acid fermentation within the cell despite the presence of oxygen.

1. True

2. False

25. All reactions involving adenosine triphosphate require the presence of magnesium.

1. True

2. False

26. Citrate synthase is the first enzyme involved in Krebs cycle activity. This enzyme is responsible for producing citric acid by converting which Kreb cycle intermediate, along with its cofactor?

1. Malic acid and NADH

2. Succinyl-CoA and GTP

3. Oxaloacetic acid and Acetyl-CoA

4. Succinic acid and Fe-S

5. None of the above

27. Most proteins necessary for mitochondrial function are encoded by genes in the cell nucleus and the corresponding proteins are imported into the mitochondrion.

1. True

2. False

28. Which of the following is not correct with regards to mitochondria?

1. The amount of ATP produced daily from a healthy individual at rest is equal to their body weight.

2. With maximal activity, the amount of ATP can increase to 1.0 kilogram per minute.

3. The cells containing mitochondria maintain approximately 250 grams of ATP

4. Mitochondria are vital to life, but they generally only occupy a small amount of cell volume at approximately 5% to 10%.

5. Each cell can contain between 1,000 to 2,500+ mitochondria with the average cell utilizing approximately 10 billion ATP daily.

29. How many offspring are fully affected (have the disease) with autosomal recessive inheritance?

1. 50%

2. 25%

3. 75%

4. 100%

5. None of these

30. Which complex of the electron transport chain contains the largest number of proteins?

1. I

2. II

3. III

4. IV

5. All contain the same number of proteins.

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Exam 3

No Time limit

You Need an 80% or Better Score To Pass.You May Retake The Exam as Many Times as You Like to Increase Your Score.

Exam 3 Study Guide

Exam 3

You Need an 80% or Better Score To Pass.
You May Retake The Exam as Many Times as You Like to Increase Your Score.