1 8/27/2015 Structure of Prokaryotes Hugh B. Fackrell

2 8/27/2015 Prokaryotes Computer Filename: Struct1.ppt

3 8/27/2015 Presentation Outline n Cell shapes n Eubacteria vs Archeobacteria n Cell Envelope n Spores n Flagella

4 8/27/2015 Background Terms & Concepts n Proteins n Membranes (membr.ppt) n Formation of lipid bilayers (membr.ppt) n Prokaryotes n Prokaryotes vs eukaryotes n Evolution of eukaryotes

5 8/27/2015 Major Groups of Organisms n Plants n Animals n Fungi n Protista n Prokaryotes n Viruses

6 8/27/2015 Prokaryotes n Characteristics –No nucleus or nuclear membrane –Microscopic –Food organic or inorganic –Some photosynthetic èBacteria n Cyanobacteria n Eubacteria èArchaea (archaebacteria)

7 8/27/2015 Prokaryotes vs Eukaryotes n Prokaryotes n No nuclear membrane n DNA in ONE molecule free in cytoplasm n No membrane bound organelles n No cytoskeleton n Eukaryotes n Nuclear membrane n DNA organized in several molecules (chromosomes) n Many different membrane bound organelles n Cytoskeleton

8 8/27/2015 Circular Bacterial DNA

9 8/27/2015 Prokaryotes (details) Size:1-10  Size:1-10  n Flagella: simple, 2 proteins n Capsule: extracellular polymer n Cell wall: usual, complex n Plasma membrane: no carbohydrates or sterols n Ribosomes: small(70S) n Cell division: binary fission

10 8/27/2015 Eukaryotes (details) Size:  Size:  n Flagella: Complex, many microtublules n Capsule: none n Cell wall: if present chemically simple n Plasma membrane:Sterols & carbohydrates n Ribosomes: large (80S) in cytoplasm –small(70S) in organelles n Cell division: mitosis

11 8/27/2015 Cell Sizes n Cell Smallest Average Largest Bacterial 0.1  1-2  0.9 mm Bacterial 0.1  1-2  0.9 mm n Animal m n Plant 1 50 ?

12 8/27/2015 Microbial Colossus n 0.5 mm n visibile to naked eye n Symbiant in gut of surgeonfish n Epulopiscium fishelsoni How does solve diffusion problems?

13 8/27/2015 Bacterial Shapes n Coccus “Berry” n Rod: (bacillus) “Rod or staff” n Vibrio: comma one turn of a helix n Spiral: rigid, open coil n Spirochete: flexible tight coil n Square:

14 8/27/2015 Coccus

15 8/27/2015 Division in Single Plane

16 8/27/2015 Bacterial Fossils 3.7 BY

17 8/27/2015 Rod

18 8/27/2015 Gold deposited by Bacteria

19 8/27/2015 Vibrio

20 8/27/2015 Magnetic Bacterium

21 8/27/2015 Spiral

22 8/27/2015 Spirochete

23 8/27/2015 Diagram of Prokaryote

24 8/27/2015 Bacterial chains

25 8/27/2015 Filamentous bacteria

26 8/27/2015 Gram Positive Cells

27 8/27/2015 Gram Negative Cells

28 8/27/2015 Bacterial Cell Walls

29 8/27/2015 Bacterial Wall [detail]

30 8/27/2015 Gm Negative Cell Wall

31 8/27/2015 Isolated Murein Layer Isolated Murein Layer

32 8/27/2015 After Peptidase hydrolysis

33 8/27/2015 Cleavage Site of Lysozyme

34 8/27/2015 Archaea: Cell Membranes n lack fatty acids n contain ethers –gylcerol diethers, bilayers –Tetraethers form monolayers –Fixed number of carbons in hydrocarbons –flexibility via pentacylic rings n Large amounts of nonpolar lipids –isoprenoids eg squalene

35 8/27/2015 Archaea: Cell Walls n NO muramic acid n NO D amino acids n pseudopeptidoglycan (Methanobacterium) –N acetyltalosaminuronic acid n glycoprotein (Halobacterium) –highly negative charge balances positive charges of sodium n Protein

36 8/27/2015 Archaea: Genetics n Half size of bacterial genomes –1900 KB vs 4700 KB (E coli) n Bacterial Similarities –Polygenic mRNA –Shine-Dalgarno sequences for ribosome binding n Eucarya Similarities – RNA polymerase II

37 8/27/2015 Bacterial Endopsore

38 8/27/2015 Questions n Diagram the structure of murein n Construct a table comparing Eubacteria and the Archeo

39 8/27/2015 Bacterial Flagellum

40 8/27/2015 Summary n Simple cells n Single circular chromosome n 1-2 microns in size n few internal compartments or organelles n Complex Cell Wall common n Cell wall unique