Please enable JavaScript.
Coggle requires JavaScript to display documents.
Prokaryotic Cell CH 13 - Coggle Diagram
Prokaryotic Cell CH 13
Definition Prokaryote — pp. 287–288 — A single‑celled organism lacking a membrane‑bound nucleus and other membrane‑enclosed organelles; includes bacteria and archaea.
Genetic matieral
Nucleoid — p. 290 — Irregular region in the cytoplasm where the cell’s circular chromosome is localized (not membrane bound).
Chromosome — p. 290 — The primary DNA molecule carrying most essential genes in prokaryotes, typically a single circular chromosome.
Plasmid — p. 290 — Small, circular, extra‑chromosomal DNA molecules that replicate independently and often carry genes (e.g., antibiotic resistance).
Cell envelope
Cell Wall — pp. 291–292 — Rigid outer layer outside the cell membrane that provides shape and protection to many prokaryotes.
Peptidoglycan — p. 291 — A mesh‑like polymer of sugars and amino acids forming the bacterial cell wall; target of some antibiotics.
Gram Positive — p. 292 — Bacteria with a thick peptidoglycan layer that retains the crystal violet stain (appears purple).
Gram Negative — p. 292 — Bacteria with a thin peptidoglycan layer plus an outer membrane; do not retain crystal violet and appear pink after staining.
Capsule (glycocalyx) — p. 292 — A sticky polysaccharide layer outside the cell wall that aids in adhesion and protects against desiccation and host defenses.
Motility & community
Flagella — p. 293 — Long, whip‑like protein structures used for locomotion in many prokaryotes (rotary motion).
Biofilm — p. 294 — A surface‑attached community of microorganisms embedded in an extracellular matrix, often more resistant to stress.
Microbial Mat — p. 295 — Multilayered, often stratified microbial communities (including phototrophs) that form thick surface mats in some environments.
Metabolism & ecology
Anaerobic organism — pp. 295–296 — Organisms that grow in the absence of oxygen; may be obligate or facultative anaerobes depending on oxygen tolerance.
Phototrophs — p. 296 — Organisms that obtain energy from light; in prokaryotes this includes photosynthetic bacteria.
Cyanobacteria — p. 297 — Photosynthetic bacteria that produce oxygen and often form mats; important in primary production and oxygenation of early Earth.
Extremophiles (Archaea) — p. 298 — Prokaryotes (mostly archaea) adapted to extreme conditions (e.g., high temperature, salinity, acidity).
Human relevance
Nutrient cycling / beneficial roles — pp. 294–296 — Prokaryotes drive biogeochemical cycles (e.g., nitrogen fixation, decomposition) and have uses in biotechnology.
Pathogenic potential — pp. 294–296 — Some prokaryotes cause disease in humans, animals, or plants through toxins, invasion, or immune evasion.