Bacterial Sporulation, Storage, and Ribosomes

Vocabulary flashcards covering key terms related to bacterial sporulation, storage structures, buoyancy mechanisms, ribosomal differences, and antibiotic selectivity.

Sporulation

Survival process in which a bacterium forms a highly resistant spore; not a method of reproduction.

Spore

Dormant, metabolically inert structure containing DNA, a few proteins, and calcium dipicolinate; highly resistant to heat, chemicals, and drying.

Dipicolinic Acid (Calcium Dipicolinate)

Unusual molecule found almost exclusively in spores; essential for germination—without it spores cannot return to vegetative growth.

Mother Cell

The bacterial cell that produces the spore and then dies once sporulation is complete.

Vegetative Cell

Actively growing, metabolically active form of a bacterium that arises after spore germination; most vulnerable stage.

Germination

Reactivation of a spore into a vegetative cell when exposed to warmth, water, and nutrients.

Tyndallization

Intermittent heating method that lets spores germinate between heat cycles and then kills the emerging vegetative cells.

Inclusion

Solid, membrane-less storage granule in bacteria used to hold insoluble nutrients such as glycogen, iron, or phosphate.

Gas Vesicle

Balloon-like, gas-filled organelle in some aquatic bacteria that inflates or deflates to control buoyancy.

Microaerophile

Bacterium that thrives in low oxygen levels; often uses gas vesicles to maintain an optimal depth in water.

Ribosome

Universal organelle that synthesizes proteins; composed of a large and a small subunit.

Svedberg Unit (S)

Measurement of sedimentation rate in a centrifuge; used to describe ribosomal subunits (e.g., 30S, 50S).

70S Ribosome

Prokaryotic ribosome made of 30S (small) and 50S (large) subunits; common antibiotic target.

80S Ribosome

Eukaryotic ribosome made of 40S (small) and 60S (large) subunits.

Selective Toxicity

Drug property that allows targeting of pathogens without harming host cells, e.g., antibiotics that bind 70S but not 80S ribosomes.

Erythromycin

Antibiotic that binds bacterial 70S ribosomes with high selective toxicity and a strong safety profile.

Chloramphenicol

Antibiotic effective against 70S ribosomes but associated with a rare, often fatal side effect—aplastic anemia.

Aplastic Anemia

Severe failure of bone marrow to produce blood cells; rare complication of chloramphenicol use.