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
7 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.
11 Scanning Electron Microscope (SEM) image..the shape?
12 Light microscopy would be even less detailed! RibosomesThis is a cartoon image created by an artist to emphasize certain structures.PlasmidsCytoplasmChromosomeFlagellumThis is a transmission electron microscopy image that inspired the cartoon.Light microscopy would be even less detailed!PlasmamembraneCell wallFigure 7-1 Page 120
13 The cytoplasm area shows the nucleoid (DNA) area at the top. 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 cytoplasm area 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 121
14 This diagram shows you a further enlargement of a TEM. The DNA double helix is further twisted to form the coils you are seeing here.DNASupercoiled DNAin chromosomeFigure 7-3 Page 121
15 Those found in the eukaryotic cytosol are 80S in “size.” Ribosomes are 70S in “size” in prokaryotes, mitochondria, and plastids.Those found in the eukaryotic cytosol are 80S in “size.”RibosomeLarge subunitof ribosomeSmall subunitof ribosomeFigure 7-4 Page 121
16 Cyanobacteria carry out photosynthesis with chlorophyll bound to proteins in thylakoid membranes PhotosyntheticmembranesFigure 7-5 Page 122This is an artificially-colored micrograph from transmission electron microscopy (TEM)
18 ? ? Transmission Electron Microscope (TEM) image..the shape?
19 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?
20 Bacterium of the Genus: Leptospira TEM or SEM?Shape?Bacterium of the Genus: Leptospira
21 What are the shapes of these disease bacteria? Vibrio choleraeHelicobacter pyloriAre they motile?If so, by what mechanism?
22 Cell Structure: Movement hookdirectional rotation?basal rings and rodanchoragerotationstiff helical flagellumflagellin proteinis rotated by “motor apparatus”in the membrane by H+ ATPaseat rates of rps(>12,000 rpm!)Taxis:movement toward stimulusExceptions:phototaxis:movement toward lightmyxomycetes, some cyanobacteria use slime, but how?spirochetes have flexible internal microtubules(endosymbiotic source of flagella in eukaryotes?)((gut parasite in termites have spirochete symbiosis))chemotaxis:movement to chemicals
23 Prokaryotic Growth Cells are generally very small Cells may double in size but only before binary fissionGrowth mostly in terms of cell number or colony size, etc.Doubling time in cell numbers may be 20 minutes in ideal conditionsCould quickly take over the earth if conditions could remain idealVery competitive in ideal environmentsUltimate survivors billion years!
24 Cell Structure: Nucleoid Nucleoid - genomeone circular DNA moleculeno histone protein associationattached to cell membranetranscription by RNA polymerasereplication by DNA polymeraseseparation of chromosomescytokinesis by furrowing70S RibosomeProcess called binary fissionNOT mitosis!Genome and copy are identicalGenome is haploidThere is no synapsisThere is no recombinationrRNA + protein + ribozymestranslation of mRNA into protein