Microbiology

Domain of single-celled organisms lacking membrane-bound nucleus: Bacteria + Archaea. Circular genome in nucleoid; 70S ribosomes; diverse…

Differential staining distinguishing Gram-positive (thick peptidoglycan, purple) from Gram-negative (thin peptidoglycan + outer LPS…

Bacterial cell-wall polymer of glycan strands (NAG-NAM) cross-linked by peptide stems. Target of β-lactam antibiotics (inhibit…

Plasmid transfer between bacteria via sex pilus (F-pilus encoded by tra operon). Major driver of horizontal gene transfer +…

Uptake of free environmental DNA by competent bacteria. Griffith 1928, Avery-MacLeod-McCarty 1944 identified DNA as transforming principle…

Cell-density-dependent coordination via diffusible autoinducers (AHL in Gram-, AIP in Gram+, AI-2 universal). Regulates biofilm, virulence,…

Surface-attached microbial community embedded in self-produced extracellular polymeric substance (EPS: polysaccharides, proteins, eDNA).…

Organism thriving in physically/chemically extreme environment. Thermophiles (Thermus, Pyrococcus, >80°C), halophiles (Halobacterium, 5M…

Dormant dehydrated structure in Bacillus, Clostridium. Extreme heat/chemical resistance; germinates on favourable conditions. Basis for…

Third domain of life (Woese 1977). Distinctive lipid membranes (ether-linked isoprenoids), histones, eukaryote-like transcription.…