CMB Lecture 2. Cell Ultrastructure PDF

Lecture 2. Cell Ultrastructure Darius Noel C. Minoza Department of Biological Sciences College of Arts and Sciences Visayas State University The Three Domains https://www.nytimes.com/2013/01/01/science/carl-woese-dies-disco vered-lifes-third-domain.html Small subunit rRNA Criteria Bacteria...

Lecture 2. Cell Ultrastructure Darius Noel C. Minoza Department of Biological Sciences College of Arts and Sciences Visayas State University The Three Domains https://www.nytimes.com/2013/01/01/science/carl-woese-dies-disco vered-lifes-third-domain.html Small subunit rRNA Criteria Bacteria Archaea Eukarya Side bulge in Has 6 Has 7 Has 7 hairpin loop nucleotides nucleotides nucleotides Protrudes Protrudes Protrudes from the stalk from the stalk from the stalk between 5th between 6th between 6th th th th and 6 base and 7 base and 7 base pair pair pair Small subunit rRNA Criteria Bacteria Archaea Eukarya Distinct Between Between Between feature positions 500 positions 585 positions 180 and 545 and 655 and 197 or 405 and 498 Similarities and Differences Criteria Bacteria Archaea Eukarya Cell type Prokaryotic Prokaryotic Eukaryotic Cell wall Peptidoglycan Variable; No Variable (Murein) murein (CHOs) Membrane Diacyl D-glycerol Isoprenoid D-glycerol, diester L-glycerol diether or Unbranched lipids L-glycerol tetraethers ester-linked Similarities and Differences Criteria Bacteria Archaea Eukarya Genetic Circular DNA Circular DNA Linear DNA material Operons Present Present Present Introns Present Present Present Similarities and Differences Criteria Bacteria Archaea Eukarya Antibiotic Present Present Present sensitivity Photosynthesis Present Present Present Mycoplasmas ❑ Formerly PPLOs (Pleuropneomonia-like organisms) ❑ Belong to Class Mollicutes ❑ Simplest and smallest cells ❑ Only class in Phylum Tenericutes ❑ Devoid of a cell wall Mycoplasma Biological Significance of Mollicutes ❑ Minimum structures for free-living existence ❑ Intermediate between viruses and bacteria in terms of size Prokaryotic Cell Ultrastructure 1. Cell membrane 8. Ribosomes 2. Bacterial cell wall 9. Cytosol 3. Capsule 10. Storage granules 4. Pili (Fimbriae) 11. Cytoskeleton 5. Bacterial flagellum 6. Nucleoid 7. Plasmids Cell Membrane: Mesosomes Cell Membrane: Magnetosome Cell Membrane: Magnetosome Cell Membrane: Chromatophores Bacterial Cell Wall Bacterial Cell Wall Peptidoglycan Gram + versus Gram - Criteria Gram (+) Gram (-) CW Thick Thin low composition peptidoglycan peptidoglycan Teichoic acids Outer layer Lipoteichoic acids (lipopolysaccharides, lipoproteins, and phospholipids Gram + versus Gram - Criteria Gram (+) Gram (-) Periplasmic Absent Present space Basal rings One pair Two pairs Gram staining Violet Red Division Firmicutes Gracilicutes Cell Wall Composition Capsule Pili (Fimbriae) Flagellum Nucleoid Plasmids Ribosomes Ribosomes Ribosomes Cytosol Storage Granules Cytoskeleton Typical Animal Cell Typical Plant Cell Lysosomes in mammalian cells Peroxisomes Endoplasmic Reticulum Golgi Apparatus Plant vacuoles Nucleus Mitochondria Chloroplasts