Which of the following statements is true regarding prion proteins?

• A. Prion proteins are beneficial to the immune system by enhancing antibody production.
• B. Prion proteins contain nucleic acids that allow them to replicate.
• C. Prion proteins are infectious agents composed entirely of protein.
• D. Prion proteins are a type of virus that affects the immune system.

Answer: (C)

Verified step by step guidance

1. Understand the nature of prion proteins: Prions are unique infectious agents composed entirely of protein, without any nucleic acids, which distinguishes them from viruses and bacteria.
2. Recognize the role of prion proteins: Unlike viruses, prions do not contain nucleic acids, so they cannot replicate in the traditional sense. Instead, they propagate by inducing abnormal folding of normal cellular proteins, particularly in the brain.
3. Clarify the misconception about prion proteins and the immune system: Prion proteins do not enhance antibody production or benefit the immune system. In fact, they are known for causing neurodegenerative diseases such as Creutzfeldt-Jakob disease.
4. Differentiate prion proteins from viruses: Prions are not viruses. Viruses contain genetic material (DNA or RNA) and can affect the immune system, whereas prions are solely protein-based and affect the nervous system.
5. Identify the correct statement: The true statement regarding prion proteins is that they are infectious agents composed entirely of protein, which is a key characteristic of prions.