Viruses, Bacteria, and Archaea

These flashcards cover key vocabulary and definitions related to viruses, bacteria, and archaea from the provided lecture notes.

Virus

A small infectious agent that can only replicate inside living cells.

Viroid

A small infectious agent composed of a short strand of circular RNA.

Prion

An infectious agent composed of protein that can trigger normal proteins to fold abnormally.

Capsid

The protein shell of a virus that encases its genetic material.

Nucleic acid

A molecule made up of nucleotides that contains the genetic information of a virus or organism.

Lytic cycle

A viral reproductive cycle that results in the destruction of the host cell.

Lysogenic cycle

A viral reproductive cycle where the virus integrates its nucleic acid into the host's genome.

AIDS (HIV)

A viral disease that attacks the immune system, caused by the human immunodeficiency virus.

Bacteriophage

A type of virus that infects bacteria.

Obligate intracellular parasite

An organism that can only reproduce inside a host cell and is not classified as living.

Emerging viruses

Viruses that are newly recognized or previously uncommon, such as Covid-19.

Antigenic drift

The gradual accumulation of mutations on the surface proteins of viruses, leading to changes in their antigens.

Gram stain

A laboratory technique used to differentiate bacterial species based on cell wall composition.

Peptidoglycan

A polymer that makes up the cell wall of bacteria, providing structural support.

Conjugation

A process by which one bacterium transfers genetic material to another through direct contact.

Transformation

The process by which bacteria take up free DNA from their environment.

Transduction

The process by which bacteriophages transfer DNA from one bacterium to another.

Pasturization

A process of heating food or liquid to kill harmful bacteria and viruses.

Cyanobacteria

Photosynthetic bacteria that are significant in nitrogen fixation.

Endospore

A dormant, tough, and non-reproductive structure produced by certain bacteria.

Methanogens

Anaerobic bacteria that produce methane during their metabolism.

Halophiles

Organisms that thrive in highly saline environments.

Thermoacidophiles

Archaea that thrive in acidic and high-temperature environments.

Epidemiology

The study of how diseases are spread and controlled in populations.

Plasmid

A small, circular piece of DNA that can replicate independently from chromosomal DNA in bacteria.

HIV

Human immunodeficiency virus, responsible for causing AIDS.

Bacterial resistance

The ability of bacteria to resist the effects of an antibiotic.

Binary fission

A form of asexual reproduction in bacteria where one cell divides into two identical cells.

Virulence factor

A property of a pathogen that enhances its ability to cause disease.

Erythromycin

An antibiotic that inhibits protein synthesis in bacteria.

Penicillin

An antibiotic that works by inhibiting cell wall synthesis in bacteria.

Viral envelope

A lipid membrane surrounding some viruses derived from the host cell.

Immune response

The reaction of the immune system to foreign substances.

SARS (Severe Acute Respiratory Syndrome)

A viral respiratory illness caused by the coronavirus SARS-CoV.

Zika virus

A mosquito-borne virus responsible for causing Zika fever.

Nucleoid

The region in prokaryotic cells where the DNA is located.

Fimbriae

Hair-like structures that help bacteria adhere to surfaces.

Budding

A process in some viruses where new viral particles are released from the host cell.

Bacteriocins

Proteins produced by bacteria that inhibit the growth of similar or closely related bacterial strains.

Infectious disease

Any disease caused by the invasion of the body by pathogens.

Common cold

A viral infectious disease of the upper respiratory tract.

Dengue fever

A mosquito-borne viral infection causing severe flu-like illness.

Antiviral drugs

Medications used specifically for treating viral infections.

Nervous system diseases

Diseases that affect the brain, spinal cord, and nerves, often caused by viral infections.

Bacterial flora

The community of bacteria that normally inhabit the human body.