Cell Biology Multiple Choice Questions on “Chemical Basis of Life – Protein Misfolding”.
1. Mercaptoethanol breaks which bonds present in the protein?
A. Hydrogen
B. Disulphide
C. Covalent
D. Non-covalent
Answer: B
Clarification: The disulfide bonds of a protein can be broken by adding a reducing agent. Mercaptoethanol is one such reducing agent that breaks the disulphide bridge into sulfhydryl groups.
2. The tertiary structure of a protein corresponds to which energy state?
A. Lowest
B. Highest
C. Intermediate
D. Ever-changing
Answer: A
Clarification: The native structure administered by the proteins which are the tertiary structure corresponds to the state of lowest energy. The tertiary structure assumed by the polypeptide chain is the most thermodynamically stable structure that can be formed by that chain.
3. The Creutzfeld-Jacob disease attacks the ______________
A. heart
B. lungs
C. kidney
D. brain
Answer: D
Clarification: The Creutzfeld-Jacob disease (CJD. is a rare and fatal disorder that attacks the brain and causes a loss of motor coordination and dementia.
4. Which protein is involved in Creutzfeld-Jacob disease (CJD.?
A. Myoglobin
B. Myosin
C. Keratin
D. Prion
Answer: D
Clarification: The Creutzfeld-Jacob disease (CJD. is a rare and fatal disorder that is caused primarily by a protein misfolding event. The prion proteins are present on the surface of nerve cells and the misfolded prion proteins are located within, forming aggregates that ultimately kill the cells.
5. The mutated and normal prion proteins associated with CJD have the same amino acid sequence.
A. True
B. False
Answer: A
Clarification: The mutated and normal versions of prion proteins are composed of same amino acid sequence, the only difference lies in the folded structure. The mutated version consists more of beta sheets whereas normal version has alpha helices.
6. Amyloid is a ____________
A. disease
B. tumor
C. fibrillar deposits
D. cell mass
Answer: C
Clarification: The fibrillar deposits found in the person with Alzheimer’s disease are termed as Amyloid. These deposits result from the self association of a polypeptide composed predominantly of beta-sheets.
7. Which peptide for the treatment of Alzheimer’s disease was approved by the government for phase I clinical trial?
A. Ab
B. Ab43
C. Aβ42
D. Aβ43
Answer: C
Clarification: Researchers at the Elan pharmaceuticals published some interesting findings in which they used the Amyloid-β-42 peptide to immunize mice and saw the mitigation in symptoms of AD.
8. Which of the following is an antibody against Aβ42 peptide?
A. Bapineuzumab
B. Cytoxan
C. Doxil
D. Adriamycin
Answer: A
Clarification: First anti-Aβ42 body came to be known as Bapineuzumab. This was used in clinical trials as a passive immunization technique for the treatment of Alzheimer’s disease.
9. Which of the following is an NSAID for Alzheimer’s disease, that lead to Phase III clinical trials?
A. Bapineuzumab
B. Alzhemed
C. Flurizan
D. Doxil
Answer: C
Clarification: Flurizan was the non-steroidal anti-inflammatory drug or NSAID for treating Alzheimer’s which reached the stage of phase III clinical trials but could proceed thereafter.
10. In addition to amyloid-β peptide, which other protein is misfolded in the brains of Alzheimer’s disease patients?
A. Alpha
B. Zau
C. Theta
D. Tau
Answer: D
Clarification: The tau-protein functions as a part of nerve cell’s cytoskeleton. In patients with Alzheimer’s this protein develops into bundles of tangle cellular filaments called neurofibrillary tangles (or NFTs) as a result of misfolding.
11. Methylthionium chloride is a __________________
A. drug
B. neuronal cell
C. cell marker
D. placebo
Answer: A
Clarification: Methylthionium chloride is a drug used for treating Alzheimer’s disease. Amyloids and neurofibrillary tangles are present in the brains of AD patients. This drug dissolves NFTs.