Chapter 6: Acellular Pathogens

These flashcards cover vocabulary related to acellular pathogens, including definitions and concepts relevant to understanding viruses and their replication mechanisms.

Acellular

Lacking a cellular structure or components, such as plasma membranes and ribosomes.

Viruses

Infectious agents composed of nucleic acid encased in a protein capsid, requiring host cells for replication.

Capsid

The protein sheath that protects the genetic material of a virus.

Prions

Infectious proteins that can replicate and cause neurodegenerative diseases without nucleic acids.

Bacteriophages

Viruses that specifically infect bacteria, possessing unique morphologies.

Lytic Cycle

A viral replication process where the host cell is lysed to release new virions.

Lysogenic Cycle

A viral replication process where viral DNA integrates into the host's genome and replicates with it.

Transformation

A horizontal gene transfer method where a bacterium takes up naked DNA from the environment.

Conjugation

A process where bacteria transfer genetic material through direct contact via a sex pilus.

Transduction

The transfer of genetic material between bacteria via a bacteriophage.

H spikes

Hemagglutinin proteins on the surface of some viruses, assisting in host recognition.

N spikes

Neuraminidase proteins on viral surfaces that facilitate the release of new virions.

Viroids

Infectious agents composed of a short strand of circular RNA, without a protein capsid.

Virusoids

Small, single-stranded RNA molecules that require helper viruses for replication.

Gene Transfer

The process by which genetic material is exchanged between organisms, enhancing genetic diversity.

Biosynthesis

The stage in the viral replication cycle where the host’s machinery is hijacked to produce viral components.

Maturation

The assembly of new virions in the viral replication cycle.

Release

The final step in viral replication where new virions exit the host cell to infect others.

RNA viruses

Viruses whose genetic material is composed of RNA, which can be single or double stranded.

Retroviruses

Viruses that reverse transcribe their RNA into DNA and integrate into the host genome.

Transposable Elements

Segments of DNA that can move around within the genome, influencing genetic makeup.

Antigenic Variation

The process by which viruses change their surface proteins to evade the host immune response.