Viruses, Viroids, and Prions

These flashcards cover the key concepts and vocabulary of viruses, viroids, and prions for an upcoming exam.

virus

Obligatory intracellular parasites that require living host cells to multiply.

obligatory intracellular parasites

Organisms that can only reproduce inside the living cells of a host.

nucleic acid

The molecule made up of nucleotides; can be either DNA or RNA in viruses.

capsid

The protein coat that surrounds the nucleic acid of a virus.

capsomeres

Protein subunits that make up the capsid.

envelope

A lipid layer that surrounds some viruses, derived from host cell membranes.

spikes

Carbohydrate-protein complexes that project from the viral envelope and attach to host cells.

host range

The spectrum of host cells that a virus can infect.

bacteriophages

Viruses that specifically infect bacteria.

Adenovirus

A type of virus known to cause respiratory infections.

bacteriophage T4

A specific strain of bacteriophage that infects E. coli.

Rabies virus

A virus that causes rabies and is known for its neurotrophic properties.

Poliovirus

The virus responsible for poliomyelitis, a contagious viral illness.

Viroid

Infectious RNA molecules that affect plants, lacking a protein coat.

prion

An infectious agent composed of protein that can cause neurodegenerative diseases.

oncogene

A gene that has the potential to cause cancer.

lysogenic cycle

The phase in which a virus integrates its DNA into the host's DNA and remains dormant.

lytic cycle

The phase in which a virus replicates and causes lysis of the host cell.

transformed cell

A cell that has been converted from normal to cancerous due to an oncogenic virus.

transduction

The process by which bacteria acquire genetic material from a virus.

blastomycosis

An infectious disease caused by the fungus Blastomyces dermatitidis, often confused with viral infections.

Antigenic shift

A major change in the antigenic properties of an influenza virus, often leading to new strains.

Antigenic drift

Small changes in the viral genome over time that result in minor antigenic changes.

provirus

Viral DNA that is integrated into the host cell's chromosome.

restrictive host

A host organism that does not support the full life cycle of a virus.

plaque assay

A method to measure the number of viral particles in a solution.

PCR

Polymerase Chain Reaction; a technique used to amplify small segments of DNA.

serological tests

Tests used to detect the presence of antibodies against viruses in the serum.

hemagglutination

The clumping of red blood cells, which can be a property of some viruses.

cytopathic effect

Visible damage caused to host cells due to viral infection.

E. coli

A bacterium commonly used in research; serves as a host for bacteriophages.

viremia

The presence of viruses in the blood.

enveloped virus

A virus that has an outer lipid membrane derived from the host cell.

nonenveloped virus

A virus that lacks a lipid envelope, having only a protein coat.

epidemic

The rapid spread of an infectious disease to a large number of people.

pandemic

An epidemic that has spread over multiple countries or continents.

zoological disease

An infectious disease that can be transmitted from animals to humans.

attenuated virus

A weakened or inactive form of a virus used in vaccines.

vector

An organism that transmits a pathogen from one host to another.

budding

The process by which an enveloped virus exits a host cell.

fusion

The merging of a virus's envelope with the host cell membrane to facilitate entry.

hemagglutinin

A glycoprotein that facilitates viral entry into host cells.

neuraminidase

An enzyme that allows viruses to exit the host cell after replication.

Retroviridae

A family of viruses that replicate in a host cell through reverse transcription.

Lentivirus

A genus of Retroviridae that includes HIV.

viral genome

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

RNA-dependent RNA polymerase

An enzyme that synthesizes RNA from an RNA template.

Virusoid

A sub-viral agent that requires a helper virus for replication.

lytic bacteriophage

A bacteriophage that causes lysis of the bacteria it infects.

malware

Computer software designed to disrupt, damage, or gain unauthorized access to computer systems.

embryonated eggs

Fertilized eggs used as a host for viral cultivation.

specificity

The ability of a virus to infect specific cell types.

viral envelope

A lipid bilayer that surrounds some viruses and assists in host cell entry.

transmission electron microscope (TEM)

A type of microscope that allows for the visualization of viruses.

viral load

The amount of virus present in a given volume of body fluid.

prevalence

The total number of cases of a disease in a specific population at a given time.

infectious dose

The minimum number of viral particles required to establish an infection.

bacteriophage lambda

A bacteriophage used as a model organism in molecular biology.

non-infectious virus

A virus that is unable to replicate or cause disease.

serotype

A distinct variation within a species of bacteria or virus.

viral pathogenesis

The biological mechanism through which viruses cause disease.

vaccine

A biological preparation that provides active acquired immunity to a particular infectious disease.