Microbiology Lecture – Fungi, Protists & Cell Structures

Vocabulary flashcards covering fungal subgroups, cellular structures, and key microbiology terminology drawn from the lecture questions.

Mold

A filamentous fungus composed of hyphae that form a mycelium; produces spores and grows best at ~25 °C.

Yeast

A unicellular, oval-shaped fungus that reproduces asexually by budding or fission; grows best at ~37 °C.

Dimorphic fungus

A fungus capable of two distinct morphologies—mold in the environment (25 °C) and yeast or spherule in the host (37 °C).

Histoplasma capsulatum

A classic dimorphic pathogen that grows as mold in soil and as yeast in human tissue, causing histoplasmosis.

Immunocompromised host

An individual with weakened immune defenses (e.g., HIV, chemotherapy) who is especially susceptible to opportunistic fungal disease.

Cell wall

A rigid layer outside the plasma membrane; made of peptidoglycan in bacteria, pseudopeptidoglycan/S-layer in archaea, chitin/glucans in fungi, and cellulose in plants/algae.

Peptidoglycan

A mesh of N-acetylglucosamine and N-acetylmuramic acid cross-linked by peptides, forming most bacterial cell walls.

Chitin

A polymer of N-acetylglucosamine that reinforces fungal cell walls and some insect exoskeletons.

Mitochondrion

Energy-producing organelle present in nearly all eukaryotes; site of oxidative phosphorylation.

Chloroplast

Photosynthetic organelle containing chlorophyll; found in plants and algae, not in animals or fungi.

Mycobacterium

Genus of acid-fast bacteria with waxy, ‘fungus-like’ colonies; belongs to the domain Bacteria (e.g., M. tuberculosis).

Mycoplasma

Small, cell-wall-less bacteria named for their ‘fungus-mimicking’ growth; domain Bacteria (e.g., M. pneumoniae).

Protist

Broad, informal term for any unicellular eukaryote (algae, protozoa, slime molds, etc.).

Protozoan

A heterotrophic, usually motile protist lacking a cell wall; often called the ‘animal-like’ protists.

Lysozyme

An antimicrobial enzyme that cleaves ß-1,4 glycosidic bonds in bacterial peptidoglycan, found in tears and saliva.

Lysosome

A membrane-bound eukaryotic organelle filled with degradative (acid hydrolase) enzymes for intracellular digestion.

Endospore

A dormant, highly resistant survival structure produced by certain bacteria (e.g., Bacillus, Clostridium); not for reproduction.

Asexual spore (fungal)

A reproductive fungal spore formed by mitosis (e.g., conidia, sporangiospores) that yields genetically identical offspring.

Sexual spore (fungal)

A reproductive fungal spore formed after meiosis following mating (e.g., zygospore, ascospore, basidiospore); increases genetic diversity.

Trophozoite

The active, feeding, motile stage in a protozoan’s life cycle, typically found inside the host.

Cyst (protozoan)

A dormant, environmentally resistant stage that allows protozoa to survive harsh conditions and facilitate transmission between hosts.