Introduction to Microbiology & Immunology

Vocabulary flashcards covering major terms from the lecture on microbiology, microbes, immunity, and vaccination.

Microbiology

The study of microscopic living organisms—microbes—and their impact on health, food, nature, and industry.

Microorganism (Microbe)

A tiny living thing such as bacteria, viruses, fungi, algae, or protozoa that is invisible to the naked eye.

Bacteria

Single-celled prokaryotes; some aid digestion or make food, while others cause disease.

Virus

An acellular particle of DNA or RNA in a protein capsid (sometimes an extra lipid envelope) that must infect a host cell to replicate.

Fungi

Eukaryotic decomposers (molds, yeasts, mushrooms) that absorb nutrients from dead or decaying matter.

Algae

Plant-like, photosynthetic microbes (often aquatic) that produce oxygen and form the base of many food chains.

Protozoa

Animal-like, mostly unicellular protists that live in water and may be free-living or parasitic.

Cyanobacteria

Photosynthetic ‘blue-green’ bacteria that released the oxygen that made Earth’s atmosphere breathable.

Bacteriophage

A virus that specifically infects and destroys bacteria; explored as an alternative to antibiotics.

Capsid

Protein coat that encloses viral genetic material and protects it until entry into a host cell.

Microscope

An instrument that magnifies small objects so they can be seen; essential for viewing microbes.

Light Microscope

Uses visible light and lenses to magnify living microbes for direct observation.

Electron Microscope

Uses electron beams for much higher magnification and resolution of microbial structures.

Microbiologist

A scientist who studies microorganisms using tools like microscopes and culture techniques.

Prokaryote

A cell lacking a nucleus and membrane-bound organelles; includes bacteria and cyanobacteria.

Eukaryote

An organism whose cells contain a true nucleus and organelles; includes protists, fungi, plants, and animals.

Monera

An obsolete kingdom that grouped all prokaryotes—mainly bacteria and cyanobacteria—together.

Lactobacillus

A ‘good’ bacterium in yogurt and the gut that aids digestion and inhibits harmful microbes.

Rhizobium

Soil bacterium living in plant roots that fixes atmospheric nitrogen into a usable form for plants.

Streptococcus

Genus of bacteria that can cause strep throat and other infections.

Mycobacterium tuberculosis

Bacterium responsible for tuberculosis (TB) in humans.

Salmonella

Bacterial genus that often causes food poisoning via contaminated food or water.

Protist

Miscellaneous kingdom of mostly unicellular eukaryotes, including protozoa, algae, and slime molds.

Animal-like Protists (Protozoa)

Heterotrophic, mobile protists that often feed on other microbes.

Plant-like Protists (Algae)

Photosynthetic protists that resemble simple plants and produce oxygen.

Fungus-like Protists

Protists that form spores and decompose matter, resembling molds and slime molds.

Mushroom

The fleshy, spore-producing ‘fruit’ of certain multicellular fungi.

Mold

Multicellular fungi that grow as fuzzy filaments on food and damp surfaces.

Yeast

Unicellular fungi used in baking and brewing; also common model organisms in research.

Immune System

The body’s overall defense network against pathogens, toxins, and abnormal cells.

Innate Immunity

Immediate, non-specific first-line defense mechanisms (skin, phagocytes, inflammation).

Adaptive Immunity

Slower, highly specific immune response involving lymphocytes that remember past pathogens.

Natural Active Immunity

Protection gained when your own immune system responds to an actual infection and forms memory cells.

Natural Passive Immunity

Temporary protection passed from mother to child (e.g., antibodies in breast milk).

Artificial Active Immunity

Immunity produced by vaccination, training the immune system without causing disease.

Artificial Passive Immunity

Short-term protection from injected antibodies (e.g., antivenom) in emergencies.

Vaccine

A biological preparation that stimulates adaptive immunity to prevent specific diseases.

Live Attenuated Vaccine

Uses weakened but living microbes to trigger strong, long-lasting immunity.

Inactivated Vaccine

Contains killed microbes; safe for most people but may require boosters.

Subunit/Recombinant Vaccine

Uses purified pieces of a pathogen (protein or polysaccharide) to elicit immunity.

Toxoid Vaccine

Contains inactivated bacterial toxins to protect against toxin-mediated diseases.

mRNA Vaccine

Delivers messenger RNA encoding an antigen so host cells produce the protein and provoke immunity.

Hand Washing

Simple hygiene practice that removes many harmful microbes and prevents disease spread.