Microbiology: Viruses, Bacteria, and the Immune Response

Comprehensive vocabulary flashcards covering key scientists, viral structures and lifecycles, bacterial characteristics and reproduction, and the three lines of immune defense.

Edward Jenner

Scientist who created the first vaccine (smallpox).

Jonas Salk

Scientist who developed the polio vaccine.

Wendell Stanley

Scientist who first crystallized a virus.

Maurice Hilleman

Scientist credited with developing a ton of modern vaccines.

Retrovirus

A virus that converts RNA to DNA using reverse transcriptase (e.g., HIV).

Lytic cycle

A viral reproductive cycle that kills the host cell right away.

Lysogenic cycle

A viral cycle in which the viral genome hides in the host DNA first before replicating.

Temperate virus

A virus capable of undergoing the lysogenic cycle.

Virulent virus

A virus that only reproduces via the lytic cycle.

Enveloped vs. Naked virus

Distinction between a virus that possesses an outer membrane (envelope) and one that does not (naked).

Virion

A complete infectious virus particle.

Prion

An infectious protein that contains no DNA or RNA.

Viroid

An infectious agent composed of naked RNA that infects plants.

Coccus

Round-shaped bacterium.

Bacillus

Rod-shaped bacterium.

Spirillum

Spiral-shaped bacterium.

Binary fission

The asexual process by which bacteria reproduce.

Conjugation

The mechanism by which bacteria share DNA with one another, spreading resistance.

Endospore

A dormant, tough structure formed by bacteria in survival mode.

Capsule & Pili

Bacterial structures that help bacteria stick to surfaces and hide from the host immune system.

Plasmid

Extra-chromosomal DNA in bacteria that often carries antibiotic resistance genes.

Antibiotics

Therapeutic substances that only work against bacteria.

Vaccines

Biological preparations containing attenuated (live weak) or inactivated (killed) pathogens to induce immunity.

1st line of defense

Non-specific external barriers including skin, mucus, tears, and stomach acid.

2nd line of defense

Non-specific internal immune responses including inflammation, fever, and phagocytes.

3rd line of defense

Specific adaptive immune response targeted against particular pathogens.

B cells

Immune cells responsible for the humoral immune response that produce antibodies.

T cells

Immune cells responsible for cell-mediated immunity that kill infected host cells.

Memory cells

Immune cells that remember a specific pathogen for rapid defense the next time it is encountered.

Common viruses

Major examples include HIV, COVID-19, Rhinovirus (common cold), Polio, and Ebola.

Common bacteria

Major examples include E. coli, Salmonella, Streptococcus (Strep), Tuberculosis (TB), Anthrax, and Tetanus.

Attenuated vaccine

A preparation containing a live, weakened version of a pathogen that stimulates strong immunity without causing severe disease.

Inactivated vaccine

A preparation containing a killed pathogen incapable of replicating, used to stimulate an immune response safely.

Humoral immunity

The branch of adaptive immunity mediated by B cells and antibodies that targets pathogens circulating in bodily fluids.

Cell-mediated immunity

The branch of adaptive immunity driven by T cells that targets and destroys infected host cells directly.