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Copyright Notice! This PowerPoint slide set is copyrighted by Ross Koning and is thereby preserved for all to use from plantphys.info for as long as that website is available. Images lacking photo credits are mine and, as long as you are engaged in non-profit educational missions, you have my permission to use my images and slides in your teaching. However, please notice that some of the images in these slides have an associated URL photo credit to provide you with the location of their original source within internet cyberspace. Those images may have separate copyright protection. If you are seeking permission for use of those images, you need to consult the original sources for such permission; they are NOT mine to give you permission.
Cellular Structure: the unit of life, one or many Biology: life study of What is Life? Growth: cell enlargement, cell number Evolution: long term adaptation Behavior: short term response to stimuli Reproduction: avoid extinction at death Metabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energy Movement: intracellular, movement, locomotion Properties of Life
Cell Associations Coccus Diplococcus Streptococcus - filamentous Staphylococcus - colonial ? Streptobacillus Cells are attached to each other by intercellular glue or a secreted sheath made of mucilaginous polysaccharides The sheath can provide antibiotic resistance too!
What shapes and associations are shown in these SEMs?
Vibrio cholerae Helicobacter pylori What are the shapes of these disease bacteria? Are they motile? If so, by what mechanism?
Theodor Schwann Prussian Zoologist Matthias Schleiden German Botanist All living organisms consist of one or more cells. 2. Some organisms are unicellular, so cells are the fundamental unit of life. 3. New cells come from pre-existing cells by cell division. We can now add: 4. Cells must show all the properties of life. 5. All cells are basically similar in chemical and structural composition. Cell Theory 1839
Cell Structure: Cytosol Gram PositiveGram Negative Mycoplasma cell membrane bilayer glycolipid, sulfolipid transport proteins cell wall-murein peptidoglycan muramic acid - peptide additional membrane bilayer glyco- sulfo-lipids cytosol regulates input/output ETS for PSN, Resp prevents dye release prevents bursting turgor pressure penicillin sensitive releases dye Water and enzymes for fermentation, glycolysis, Krebs cycle, Calvin cycle, naked circular DNA for transcription, 70S ribosomes for translation
Figure 7-2 Page 121 Plasma membrane Cell wall Cytoplasm This cartoon is not labeled, so it merely acts as a key, to orient the viewer to the enlarged portion of the TEM image. The cytosol area (labeled cytoplasm)shows the nucleoid (DNA) area at the top. The cell membrane shows that it is a bilayer. The cell wall shows that it is multilayered. Is this example Gram+ or Gram?
Figure 7-1 Page 107 This is a cartoon image created by an artist to emphasize certain structures. This is the transmission electron microscopy image that inspired the cartoon. Light microscopy would be even less detailed! Cytosol
Figure 7-2 Page 108 These are an SEM (above) and TEM (below). The DNA double helix is highly twisted to form the coils you are seeing here. The area inside the cell including the naked, circular DNA molecule (lacking DNA- binding proteins) is called the nucleoid; it is not a nucleus! The bacterium is prokaryotic (before-nucleus). The functions of the nucleoid are transcription (making mRNA), and replication (making a copy of DNA prior to cell division).
Figure 7-4 Page 121 (3 rd edition: not in current edition!) Large subunit of ribosome Small subunit of ribosome Ribosome Ribosomes are 70S in size in prokaryotes, mitochondria, and plastids. Those found in the eukaryotic cytosol are 80S in size. The function of the ribosome in both kinds of cells is translation; the synthesis of protein from the information in mRNA.
Cell Structure: Nucleoid mRNA transcription by RNA polymerase one circular DNA molecule no histone protein association attached to cell membrane Nucleoid - genome translation of mRNA into protein rRNA + protein + ribozymes 70S Ribosome
Prokaryotic Growth Cells are generally very small Cells may double in volume, but only before binary fission Growth is mostly in terms of cell number or colony size, etc. The doubling time in cell numbers may be 20 minutes in ideal conditions Bacteria could quickly take over the earth if conditions could remain ideal They are very competitive, but often shed by- products that inhibit their own survival, so ideal conditions are usually not sustainable. They are ultimate survivors billion years!
Cell Structure: Nucleoid one circular DNA molecule no histone protein association attached to cell membrane separation of chromosomes DNA replication by DNA polymerase Nucleoid - genome cytokinesis by furrowing Process called binary fission NOT mitosis! Genome and copy are identical Genome is haploid There is no synapsis There is no recombination
? ? Transmission Electron Microscope (TEM) image..the shape?
Cyanobacterial Vegetative Cell: cell wall cell membrane lipid droplet nucleoid polyhedral body RuBisCO cyanophycin thylakoids cyanophycean starch gas vacuole polyphosphate granule mesosome 70S ribosome light (ETS) reactions Calvin cycle sugar synthesis glycolysis Krebs cycle CO CH 2 O ETS reactions cytosol light chlorophyll H2OH2O O2O2 Photosynthesis Respiration CH 2 O + H 2 O + energy O 2 + CO 2
Sulfolobus acidocaldarius Extremophile Sulfur metabolism pH 1 to 6 75°C Optimum Strict aerobe Partial monolayer (C40) membranes Multiple DNA Circles Introns in DNA DNA binding proteins rRNA similarity RNA synthase similarity Operon style regulation 70S ribosomes TEM or SEM? Of Archaeon Shape?