Presentation on theme: "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."— Presentation transcript:
1 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.
2 Biology: What is Life? life study of Properties of Life Cellular Structure: the unit of life, one or manyMetabolism: photosynthesis, respiration, fermentation, digestion, gas exchange, secretion, excretion, circulation--processing materials and energyGrowth: cell enlargement, cell numberMovement: intracellular, movement, locomotionReproduction: avoid extinction at deathBehavior: short term response to stimuliEvolution: long term adaptation
8 Cells are attached to each other by intercellular glue or a secreted sheath made of mucilaginous polysaccharidesCell AssociationsCoccusDiplococcusThe sheath can provide antibiotic resistance too!Streptococcus - filamentousStaphylococcus - colonial?Streptobacillus
9 What shapes and associations are shown in these SEMs?
10 What are the shapes of these disease bacteria? Vibrio choleraeHelicobacter pyloriAre they motile?If so, by what mechanism?
12 Cell Theory 1839 Theodor Schwann Prussian Zoologist 1810-1882 Theodor SchwannPrussian ZoologistMatthias SchleidenGerman Botanist1. 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.
14 Cell Structure: Cytosol MycoplasmaWater and enzymes for fermentation, glycolysis, Kreb’s cycle, Calvin cycle, naked circular DNA for transcription, 70S ribosomes for translationcell membrane bilayerglycolipid, sulfolipidtransport proteinscytosolregulates input/outputETS for PSN, RespGram PositiveGram Negativecell wall-mureinpeptidoglycanmuramic acid - peptideprevents dye releaseprevents burstingturgor pressurepenicillin sensitiveadditionalmembrane bilayerglyco- sulfo-lipidsreleases dye
15 Is this example Gram+ or Gram−? This cartoon is not labeled, so it merely acts as a key, to orient the viewer to the enlarged portion of the TEM image.CytoplasmThe 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.PlasmamembraneCell wallFigure 7-2 Page 121Is this example Gram+ or Gram−?
16 Light microscopy would be even less detailed! This is a cartoon image created by an artist to emphasize certain structures.CytosolThis is the transmission electron microscopy image that inspired the cartoon.Light microscopy would be even less detailed!Figure 7-1 Page 107
17 The bacterium is prokaryotic (before-nucleus). 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 7-2 Page 108
18 Figure 7-4 Page 121 (3rd edition: not in current edition!) 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.RibosomeLarge subunitof ribosomeSmall subunitof ribosomeFigure 7-4 Page 121 (3rd edition: not in current edition!)
19 Cell Structure: Nucleoid Nucleoid - genomeone circular DNA moleculeno histone protein associationattached to cell membranemRNA transcription by RNA polymerase70S RibosomerRNA + protein + ribozymestranslation of mRNA into protein
20 Prokaryotic Growth Cells are generally very small Cells may double in volume, but only before binary fissionGrowth is mostly in terms of cell number or colony size, etc.The doubling time in cell numbers may be 20 minutes in ideal conditionsBacteria could quickly take over the earth if conditions could remain idealThey 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!
21 Cell Structure: Nucleoid Nucleoid - genomeone circular DNA moleculeno histone protein associationattached to cell membraneDNA replication by DNA polymeraseseparation of chromosomescytokinesis by furrowingProcess called binary fissionNOT mitosis!Genome and copy are identicalGenome is haploidThere is no synapsisThere is no recombination
22 ? ? Transmission Electron Microscope (TEM) image..the shape?
24 Sulfolobus acidocaldarius TEM or SEM? Of ArchaeonExtremophileSulfur metabolismpH 1 to 675°C OptimumStrict aerobePartial monolayer (C40) membranesMultiple DNA CirclesIntrons in DNADNA binding proteinsrRNA similarityRNA synthase similarityOperon style regulation70S ribosomesShape?