Viruses and Other Acellular Infectious Agents

A collection of flashcards designed to help reinforce and review key vocabulary and concepts related to viruses and acellular infectious agents as covered in the lecture notes.

Virology

The study of viruses.

Bacteriophage

A virus that infects bacteria.

Phage

A term used synonymously with bacteriophage.

Tropism

The tendency of a virus to infect specific tissues or cell types.

Virion

A mature virus particle.

Capsid

The protein coat of a virus.

Envelope

A lipid membrane surrounding some viruses.

Nucleocapsid

The combination of viral nucleic acid and protein coat.

Extracellular

Viruses that are inactive outside of living cells.

Intracellular

Viruses that use host cells to replicate.

Enveloped virus

A virus with a lipid membrane surrounding its capsid.

Nonenveloped virus

A virus that lacks a lipid membrane.

Icosahedral capsid

The most efficient structure to enclose space, consisting of 20 triangular faces.

Helical capsid

A hollow tube-like structure formed from protomers.

Complex symmetry

Viruses with structures that do not fit into helical or icosahedral categories.

Capsomers

Ring or knob-shaped units composing the capsid.

Pentamer

A capsomer consisting of five protomers.

Hexamer

A capsomer consisting of six protomers.

Prophage

The form of a virus that remains within its host cell.

Lysogeny

The relationship between a temperate phage and its host.

Cytopathic effects (CPEs)

Degenerative changes in host cells due to viral infection.

Persistent infection

An infection that may last for years without killing the host cell.

Viral replication complexes

Enclosed machinery needed for viral genome replication.

Burst size

The number of new viruses produced per infected cell.

Lytic cycle

A phase of viral replication where the virus multiplies and causes host cell lysis.

Lysogenic cycle

A phase where the virus integrates its genome into the host chromosome and remains dormant.

Viral genome

The genetic material of a virus, which can be DNA or RNA.

Single-stranded RNA

A type of viral genome consisting of a single strand of RNA.

Double-stranded DNA

A type of viral genome consisting of two strands of DNA.

Ligand

A molecule that binds to another (receptor) molecule.

Receptor-mediated endocytosis

A method of viral entry into host cells involving receptor binding.

Budding release

A process through which enveloped viruses exit host cells without causing lysis.

Lysis

The breaking down of a cell, resulting in the release of viral particles.

Envelope proteins

Proteins projected from the viral envelope that aid in attachment and identification.

RNA silencing

A mechanism by which viroids can cause diseases in plants.

Plaque-forming unit (PFU)

A unit used to measure the number of viable viruses in a sample.

Cytosol

The liquid found inside cells where viral components are released.

Infection

The process of a virus entering and multiplying within a host organism.

Synthesis

The step in the viral life cycle where viral components are produced.

Assembly

The process of putting together viral components to form new virions.

Virulent phage

A bacteriophage that causes lysis of the host cell immediately upon infection.

Temperate phage

A bacteriophage that can choose between lytic and lysogenic replication.

Chronic infection

An infection that persists over a long period, often without cell death.

Plasmid

A small, circular DNA molecule separate from chromosomal DNA, commonly found in bacteria.

Protoplast

A plant cell that has had its cell wall removed.

Embryonated eggs

Fertilized eggs used as hosts for growing viruses in laboratory settings.

Gene expression

The process by which information from a gene is used to create a functional product.

Transformation

The process of a normal cell becoming malignant due to viral infection.

Neglected tropical diseases

Infectious diseases prevalent in tropical and subtropical conditions.

Nucleic acid-based agents

Include viroids and satellites that are based solely on nucleic acids.

Model organisms

Organisms used in laboratory settings to study biological processes.

Microbial world

Refers to the diverse group of microorganisms including bacteria, viruses, fungi, and protozoa.

Vector

An agent that carries and transmits a pathogen into another living organism.

Pathogen

A microorganism that can cause disease.

Infectious disease

A disease caused by the invasion of the body by pathogenic microorganisms.

Neurodegenerative diseases

Disorders characterized by the progressive degeneration of the structure and function of the nervous system.

Scrapie

A prion disease affecting sheep.

Bovine spongiform encephalopathy (BSE)

A prion disease commonly known as mad cow disease.

Kuru

A prion disease associated with cannibalism in New Guinea.

Gerstmann-Sträussler-Scheinker syndrome

A rare inherited prion disease.

Prion

An infectious agent composed solely of protein.

Nonenveloped viruses

Viruses that lack an envelope; usually more resistant to environmental factors.

Acellular

Referring to entities, such as viruses, that are not composed of cells.

Aquatic ecosystem

An ecosystem based in water environments where viruses play significant ecological roles.

Viral ligand

A molecule on a virus that attaches to a receptor on a host cell.

Phage display

Technique used to study protein interactions or functions using bacteriophages.

Ribosomes

Cellular structures responsible for protein synthesis, often hijacked by viruses.

Enzymatic activity

The catalytic function of a protein that facilitates biochemical reactions.

Genetic material

The DNA or RNA carried by a virus.

Microbiome

The community of microorganisms living in a particular environment, especially the human gut.

Cancer cells

Cells that have uncontrollably multiplied and can invade other tissues.

Bacteriophages

Viruses that infect and replicate within bacteria.

Plant viruses

Viruses that infect plants, often causing significant agricultural impact.

Animal viruses

Viruses that infect animal cells, including humans.

Protists

Diverse group of eukaryotic microorganisms, which can also be infected by viruses.