Q: Which of the following statements about the propagation of PrP\textsuperscript{Sc} is correct?

PrP\textsuperscript{Sc} can induce normal PrP\textsuperscript{C} to adopt the misfolded, pathogenic conformation.

Question 1

Which of the following best explains why prions are considered unique infectious agents compared to viruses and bacteria?

Accepted Answer

Prions are composed solely of protein and lack nucleic acids, yet can transmit disease.

Question 2

A patient receives a neural implant of healthy fetal cells to treat Parkinson’s disease. Years later, postmortem analysis reveals prion aggregates in the implanted cells. What does this observation most directly demonstrate?

Accepted Answer

Prions can induce misfolding in normal proteins and spread from cell to cell.

Question 3

Which structural change occurs when the normal prion protein (PrP	extsuperscript{C}) converts to the disease-causing form (PrP	extsuperscript{Sc})?

Accepted Answer

A decrease in $\alpha$-helical content and an increase in $\beta$-sheet content.

Question 4

Which of the following diseases is NOT currently classified as a prion disease, but is thought to involve prion-like mechanisms?

Accepted Answer

Type 2 Diabetes

Question 5

A mouse genetically engineered to lack PrP	extsuperscript{C} (PrP-) is tested for long-term memory using a maze. What is the most likely outcome?

Accepted Answer

The mouse will show a significant deficit in long-term memory compared to wildtype mice.

Question 6

Which of the following statements about the PRNP gene is correct?

Accepted Answer

It encodes the prion protein, and mutations can be inherited in an autosomal dominant manner.

Question 7

Which of the following best describes the role of intrinsically disordered proteins (IDPs) in cellular function?

Accepted Answer

IDPs can participate in molecular recognition, signaling, and scaffolding due to their flexibility.

Question 8

Which of the following is a key feature of amyloid plaques in Alzheimer’s disease?

Accepted Answer

They consist of amyloid-beta complexes that cause mitochondrial damage and cell death.

Question 9

A patient inherits a mutation in the PRNP gene. Which of the following best describes the likely inheritance pattern and consequence?

Accepted Answer

Autosomal dominant; the patient is at risk for prion disease even with one mutated allele.

Question 10

Which of the following best explains why prion diseases are classified as 'spongiform encephalopathies'?

Accepted Answer

They cause the brain to become spongy due to the formation of vacuoles from neuronal death.

Question 11

Which of the following statements about the propagation of PrP	extsuperscript{Sc} is correct?

Accepted Answer

PrP	extsuperscript{Sc} can induce normal PrP	extsuperscript{C} to adopt the misfolded, pathogenic conformation.

Question 12

Which of the following best describes the difference between amyloids and prions?

Accepted Answer

Prions are a subset of amyloids, but not all amyloids are transmissible.

Question 13

Which of the following amino acid compositions is most likely to be found in an intrinsically disordered region (IDR) of a protein?

Accepted Answer

Enriched in polar and charged residues such as Lys, Glu, Ser, and Pro.

Question 14

Which of the following best explains the 'coupled folding and binding' mechanism of IDPs?

Accepted Answer

IDPs adopt a defined structure only upon binding to their molecular partners.

Question 15

Which of the following is a common feature of neurodegenerative diseases such as Alzheimer's, ALS, and prion diseases?

Accepted Answer

Formation of protein aggregates that disrupt cellular function.

Question 16

A scientist observes that a protein forms fibrils and aggregates in the brain, but is not transmissible between individuals. Which of the following best describes this protein?

Accepted Answer

It is an amyloid, but not a prion.

Question 17

Which of the following best describes the process by which prion diseases can be transmitted horizontally?

Accepted Answer

By the spread of misfolded prion proteins from cell to cell.

Question 18

Which of the following is a proposed function of the normal prion protein (PrP	extsuperscript{C}) in the brain?

Accepted Answer

Stabilizing neuronal connections and supporting memory formation.

Question 19

Which of the following best explains why prion diseases are difficult to treat?

Accepted Answer

Prions are highly stable, resistant to proteases, and lack nucleic acids, making them hard to target.

Prions and Intrinsically Disordered Proteins: Structure, Function, and Disease

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