Viruses and Prions

These flashcards cover key concepts related to viruses and prions based on the lecture notes.

What defines viruses as obligate intracellular parasites?

Viruses require a living host cell to replicate and cannot live independently.

What is a key characteristic of viruses regarding their structure?

Viruses are not cellular in nature and have a compact structure that includes a protein shell (capsid) surrounding nucleic acid.

What are the types of nucleic acid found in viral genomes?

Viral genomes can be either DNA or RNA, and can be single-stranded or double-stranded.

Name one property that viruses lack compared to living organisms.

Viruses lack enzymes for most metabolic processes.

What is the process of viral multiplication?

Viral multiplication includes steps such as adsorption, penetration, uncoating, synthesis, assembly, and release.

How do viruses attach to host cells?

Viruses attach to host cells by specific binding of their spikes to cell receptors.

What defines a lytic viral infection?

In a lytic infection, viruses go through all stages of multiplication quickly, harming or killing the host cell.

What happens during a latent viral infection?

In latent infections, the virus remains dormant in the host cell and integrates into the host genome, typically without causing symptoms.

What are prions?

Prions are misfolded proteins that cause transmissible spongiform encephalopathies and contain no nucleic acids.

What diseases are caused by prions?

Prion diseases include Creutzfeldt-Jakob Syndrome in humans and BSE (mad cow disease) in cattle.

What is the outcome of viral infections in terms of immune response?

Viral infections often elicit immune responses that can cause symptoms including inflammation and fever.

What is the difference between chronic and lytic infections?

Chronic infections involve slow multiplication of the virus with potential for mild symptoms, while lytic infections involve rapid multiplication causing severe harm to the host.

What is the definition of oncogenic infections?

Oncogenic infections can transform host cells into cancer cells but may not complete all stages of viral multiplication.

How do viruses replicate their genome?

Viruses replicate their genome and synthesize proteins using the host cell's genetic machinery.

What role do viral glycoproteins play during the infection process?

Viral glycoproteins are crucial for the virus to attach to the host cell and for the assembly of new virions.