Viruses, Viroids, and Prions

This set of flashcards covers key vocabulary, definitions, and concepts related to viruses, viroids, and prions as discussed in the lecture.

Capsid

The protein coat surrounding the nucleic acid in a virus.

Envelope

A lipid layer external to the capsid in some viruses.

Spike

Protein projections that may be present on the surface of a virus's envelope.

Bacteriophage

A virus that infects and replicates within bacteria.

Lytic cycle

The viral multiplication method which results in the destruction of the host cell.

Lysogenic cycle

A viral replication process where the viral genome integrates into the host's DNA.

Prophage

A bacteriophage that has inserted its DNA into a bacterial host’s chromosome.

Provirus

A viral genome that integrates into the host's DNA in animal cells.

Latent infection

A type of viral infection where the virus remains inactive within the host.

Persistent infection

A viral infection that is long-lasting where infectious virus builds up.

Prions

Infectious proteins that cause neurodegenerative diseases.

Viroids

Naked RNA molecules that infect plants, lacking a protein coat.

Virion

A complete virus particle that is capable of infection.

Host range

The specific species or types of cells a virus can infect.

Obligate intracellular parasites

Organisms that can only multiply within living cells.

Antigen

A substance that induces an immune response, often present on the virus’s surface.

Glycoprotein spikes

Protein-carbohydrate complexes on the viral envelope that assist in attachment to host cells.

Biosynthesis

The production of viral components inside a host cell.

Maturation

The assembly of new virus particles from their components inside the host cell.

Release

The exit of new virions from the host cell, usually resulting in cell death.

Burst time

The time taken for new virions to be released after viral infection.

Burst size

The number of new virions released from a single infected cell.

Antigenic variation

Changes in virus antigens that alter immune recognition.

Viral taxonomy

The classification of viruses into families and genera.

-viridae

Suffix used for viral families.

-virus

Suffix used for viral genera.

Viral species

A group of viruses sharing the same genetic information and ecological niche.

Prophage

The genetic material of a bacteriophage that has integrated into the host's chromosome.

Temperate bacteriophage

A bacteriophage that can undergo both lytic and lysogenic cycles.

Retrovirus

A type of virus that uses reverse transcriptase to replicate its RNA genome.

RNA-dependent RNA polymerase

An enzyme that replicates RNA genomes.

Oncogene

A mutated form of a normal gene involved in the regulation of cell growth.

Viral oncogenesis

The process by which viruses can cause cancer.

Zoonosis

Transmission of diseases from animals to humans.

Covid-19

A disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Spongiform encephalopathies

A group of progressive neurodegenerative disorders caused by prions.

Kuru

A fatal neurodegenerative disease associated with prion infection among the Fore people.

Chronic wasting disease

A prion disease affecting deer and elk.

Viroid diseases

Plant diseases caused by infectious RNA molecules without a protein coat.

Megavirus

A newly discovered large virus that infects amoebas.

Pandoravirus

A recently discovered genus of large viruses that infect amoebas.

Infectious proteins

Proteins that can induce abnormal folding of normal cellular proteins.

Human papillomavirus

A virus that causes cervical and skin cancer.

Hepatitis viruses

Viruses that cause liver inflammation and can lead to cancer.

Antibody

A protein produced by the immune system to neutralize pathogens.

Endocytosis

The process by which a cell takes in materials by engulfing them.

Fusion

The process by which a virus envelope merges with the host cell membrane.

Uncoating

The release of the viral genome into the host cell after entry.

Nucleic acids

Molecules, such as DNA or RNA, that contain genetic information.

Metabolic machinery

The cellular components involved in the metabolism and energy production of cells.

Viral genes

DNA or RNA segments that provide instructions for making viral components.