Chapter 4:Prokaryotic Cells

These flashcards cover key vocabulary terms related to prokaryotic cells, their structures, functions, and classifications for review for the Micro 20 Exam.

Piezophile/Barophile

Pressure-loving organism.

Acidophile

Acid-loving organism.

Lithophile

Lives inside rocks.

Halophile

Salt-loving organism.

Staphylococcus

Cluster of spherical cells.

Streptococcus

Chain of spherical cells.

Vibrio

Curved rod (‘comma’/bratwurst shape).

Bacillus

Rod (‘hot dog’ shape).

Gram-positive cell wall

Thick peptidoglycan; contains teichoic acids.

Gram-negative cell wall

Thin peptidoglycan; outer membrane; LPS with toxic Lipid A.

Peptidoglycan subunits

NAM + NAG linked by tetrapeptide bridges.

Lipopolysaccharide (LPS)

Found in Gram-negative bacteria; Lipid A is the endotoxin.

Inclusion bodies

Storage granules (e.g., glycogen, polyphosphate).

Mycolic acid

Waxy lipid in Mycobacteria cell walls; detected by acid-fast stain.

Fluid Mosaic Model

Membrane = phospholipid bilayer with proteins.

Biofilms

Microbial communities on surfaces (e.g., catheters); involve quorum sensing; medically important.

Pili

Used for DNA transfer (conjugation).

Fimbriae

Numerous, short; used for adhesion.

Capsule

Protective coating; prevents phagocytosis, increases virulence.

Lophotrichous

Tuft of flagella at one end.

Peritrichous

Flagella distributed all over surface.

Amphitrichous

One flagellum at each end.

Chemotaxis

Movement toward/away from chemicals.

Phototaxis

Movement toward light.

Gravitaxis

Movement toward gravity.

Prokaryotic ribosome

70S.

Eukaryotic ribosome

80S.

Svedberg unit (S)

Sedimentation rate (not linear).

Cyanobacteria

Photosynthetic, oxygenic.

Purple sulfur bacteria

Photosynthetic, anoxygenic.

Methanogens

Archaea; produce methane in anaerobic environments (e.g., cow gut).

Mycoplasmas

Smallest living cells; lack cell wall.

Endospores

Dormant, resistant forms; produced by Bacillus & Clostridium.

Plasmids

Extrachromosomal DNA; carry resistance/virulence; transferable.

Characteristics of living things

Growth, metabolism, response to stimuli, homeostasis, reproduction.

Viruses

Non-living; obligate intracellular parasites.

Spirillum

Rigid corkscrew-shaped bacteria.

Spirochete

Flexible, slinky-like bacteria.