Chapter 13 [Part 1/1]

Virus

A non-cellular infectious agent composed of genetic material (DNA or RNA) surrounded by a protein coat called a capsid.

Virion

The complete, infective form of a virus outside a host cell, consisting of the viral genetic material and the capsid.

Acellular

Referring to organisms or entities that do not consist of cells.

Lytic cycle

The process by which a virus infects a host cell, replicates, and causes the cell to burst, releasing new virions.

Lysogenic cycle

A viral replication process in which the virus integrates its genetic material into the host cell's genome, allowing it to replicate along with the host cell's DNA.

Capsid

The protein shell that encases the viral genome and protects it.

Prion

An infectious agent composed entirely of protein, capable of causing abnormal folding of normal cellular proteins.

Viroid

A small infectious agent composed of a short strand of circular RNA which does not code for proteins and causes diseases primarily in plants.

Obligate intracellular parasite

An organism that can only reproduce within a living host cell.

Icosahedron

A common viral shape characterized by a polyhedral structure made up of 20 triangular faces.

Genome

The complete set of genetic information in an organism, including all of its genes.

Bacteriophage

A type of virus that specifically infects and replicates within bacteria.

Zoonotic infection

An infectious disease that is transmitted from animals to humans.

Envelope

A lipid membrane that surrounds some viruses, enabling them to evade the host immune system.

Capsomer

Protein subunits that make up the capsid of a virus.

Spike proteins

Proteins on the surface of some viruses that facilitate the virus's entry into host cells.

Epidemiology

The branch of medicine that deals with the incidence, distribution, and control of diseases.

Antigen

A substance that induces an immune response, often associated with the ability to provoke antibody production.

Transduction

The process by which viruses introduce new genetic material into a host cell.

Replication fork

The area where the DNA double helix is unwound to allow for replication.

Endocytosis

The process by which a cell engulfs external substances, allowing viruses with an envelope to enter the cell.

Pathogenicity

The ability of an organism to cause disease.

Host cell

A living cell in which a virus or parasite reproduces.

Symptoms

Physical or mental features that are regarded as indicating a condition of disease.

Pathogen

An organism that causes disease, particularly a virus, bacterium, or other microbe.

Chaperone proteins

Proteins that assist in the correct folding and assembly of other proteins.

Misfolding

The incorrect folding of proteins, which can lead to functional abnormalities and diseases.