Characterizing and Classifying Viruses, Virophages, Viroids, and Prions

Virus

Nonliving infectious particle

Obligate intracellular parasites

Viruses that can only replicate inside a host cell

ATP-generating mechanism

Viruses lack the ability to generate ATP

Nucleocapsid

Structure formed by the capsid and nucleic acid of a virus

Capsid

Protein coat that encloses and protects the nucleic acid of a virus

Enveloped viruses

Viruses with a lipid bilayer envelope derived from the host cell membrane

Naked viruses

Viruses without an envelope

Viral envelope

Protects the nucleic acid when the virion is outside the host cell and is essential for infectivity

Burst time

Time from infection to the release of new virions

Burst size

Number of virions released from a host cell

Lysogeny

State in which a virus inserts its DNA into the host genome and becomes inactive

Transduction

Process by which a bacteriophage transfers bacterial genes from one bacterium to another

Lysis

Donor cell ruptures and releases phage particles containing bacterial DNA.

Phage

Virus that infects bacteria and carries bacterial DNA.

Recombination

Process where genetic material from different sources combines to create a new genotype.

Coronavirus

Virus named SARS-CoV-2 by WHO

Aerosolized

Virus particles suspended in the air

Transmission

Spread of virus from person-to-person or via indirect contact

Enveloped virus

Virus with a lipid membrane surrounding the protein coat.

Genome

Complete set of genes or genetic material present in a cell or organism.

ACE2

Protein on host cells to which the S-proteins on viral envelope bind

Incubation time

Time from exposure to first symptoms

Asymptomatic

Showing no symptoms of the disease despite being infected.

Hypoxia

Deficiency in the amount of oxygen reaching the tissues.

PCR test

Test to amplify and detect viral genetic material in a person's secretions

Antigen test

Test to detect viral proteins

Antibody test

Blood test to determine the presence of antibodies post-infection

Prions

Proteinaceous infectious particles causing slow and deadly neurological diseases

PrPC

Normal cellular prion protein involved in the regulation of cell death and differentiation.

PrPSc

Abnormal protein accumulating in brain cells

Creutzfeldt-Jakob Disease

Progressive

Bovine Spongioform Encephalopathy

Fatal disease affecting the brain of cattle

vCJD

Variant form of Creutzfeldt-Jakob Disease acquired through ingestion of contaminated beef.

Plant Viruses

Viruses that enter plants through wounds or via insects

Viroids

Infectious