Cell Biology

... from active transport to vesicles


Prokaryotes are microbial cells lacking a nuclear membrane. Eukaryotes contain membrane bound organelles and nuclear material enclosed by a nuclear membraneProkaryote structureCell wall.

The Eubacteria of Kingdom Monera, commonly called bacteria • Eubacteria :
1. Prokaryotic organisms without a nuclear membrane
2. Eubacterial rRNA and no introns in genome
3. Membrane lipids are primarily diacyl glycerol ethers
4. Cell walls contain thick (gram+) or thin layers of peptidoglycan (gram-)

Prokaryote : Physiology & Communication - Genetics & Biochemistry - Phyla :

The Archaea, or Archaeobacteria • The Archaea :
1. Prokaryotic organisms without a nuclear membrane
2. Archaeobacterial rRNA -- introns in genome
3. Membrane lipids are unusual -- primarily isoprenoid glycerol diether or diglycerol tetraether derivatives
4. The cell wall does not contain peptidoglycan (gram-)

Table  Comparisons of Eubacteria, Archaea, and Eukaryotes ^ Taxonomy ^ Phylogenetics
^ History of taxonomic concepts ^ Archaea Eocyte Tree ^ Bacteria ^

There are three groups of Archaea, which also called extremophiles: Methanogens are poisoned by O2, Thermophiles live in extreme temperatures, and Halophiles live in highly saline environments

The Five Kingdom system was proposed in 1969: Monera (prokaryotes), Protista, Plantae, Fungi, Animalia. Woese and Fox later proposed a Three Domain system: Eubacteria, Archaea, and Eukaryotes (the term Urkaryotes was proposed for ancestors of eukaryotes prior to their endosymbiotic acquisition of mitochondria and chloroplasts from prokaryotes). Margulis and Schwartz proposed that Kingdom Protista be replaced by Protoctista to reflect inclusion of multicellular organisms that did fit into the other three eukaryotic kingdoms.

Prokaryote structure : Prokaryote taxonomy & phylogeny : Eubacteria and Archaea : Eubacteria : The Archaea : Table  Comparisons of Eubacteria, Archaea, and Eukaryotes - The Three Domains View Quicktime Movie - Genetic Data movie of phylogram construction - image cladogram - image Tree of Life— Lateral Gene Transfer Diagram - image uprooted tree - image 16S ribosomal RNA - image The "Shrub of Life" - image A comparison of key characteristics from the three domains of life - enlarged – Evolution and Phylogenetics - Animations and Images - Genomics Animations and Images - Proteins & Proteomics - Animations and Images – - Biodiversity - Animations and Images – Microbial Diversity – Animations and Images – Emerging Infectious Diseases - Animations and Images – HIV & AIDS - Animations and Images : Virtual Cell Textbook - Cell Biology :

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