2.2 Prokaryotic Cells IB Biology Slide 2 Slide 3 Prokaryotic
Cells First organisms to evolve on Earth 3.5 billion years ago
cyanobacteria Simplest cell structure Eubacteria and Archaea Slide
4 Origin of Life Miller-Urey Experiment Stimulated pre-biotic life
conditions in the lab for 1 week Ammonia (NH3) Methane (CH4)
Hydrogen (H2) Water (H2O) Spark of electricity (simulate lightning)
Slide 5 Slide 6 Origin of Life Experiment Results Organic compounds
found Amino acids which make up proteins of living things
Experiment not supported today other than to show that life can
arise from a chemical origin Recall: This is evidence supporting
the cell theory all cells come from preexisting cells Slide 7 DVD:
Cosmos, Carl Sagan 1980s TV series narrated and produced by Carl
Sagan He was an astronomer, cosmologist, astrophysicist Episode 2:
Chapter 10 One Voice in the Cosmic Fugue Time: 46-52 min Slide 8
Prokaryotes: Eubacteria vs. Archaea No true nucleus Heterotrophs or
autotrophs Most have cell wall with peptidoglycan Live everywhere
Eg. Bacteria cyanobacteria No true nucleus Heterotrophs Cell wall
with no peptidoglycan Live in extreme environments Salt
(halophiles) Heat (thermophiles) Methane (methanogens) Slide 9
Prokaryote Properties Small size Unicellular One cell must carry
out all the functions of life Found everywhere Can live in various
extreme environments Found in soil, water, volcanoes, intestines
and skin Slide 10 Metabolic Properties 1. Fermentation Convert
lactose (sugar) into lactic acid for yogurt production 2.
Photosynthesis Blue-green bacteria produce their own food 3.
Nitrogen Fixation Convert nitrogen from air into nitrogen compounds
useful in soil Slide 11 Prokaryotic Structures No nucleus No
mitochondria No membrane bound organelles Slide 12 Escherichia coli
Scanning Electron Microscope Transmission Electron Microscope Found
in your gut Slide 13 Cell wall Carbohydrate and protein Protection
Maintains shape Prevent bursting Cell (plasma) membrane
Phospholipid bilayer Partially permeable controls what enters and
exits the cell CELL MEMBRANE CYTOPLASM E. Coli Micrograph Slide 14
Cytoplasm Fluid, gel-like Contains free floating molecules Enzymes,
ribosomes Location of chemical reactions of metabolism Nucleiod
Small amount of circular DNA with no protein Controls cell
activities Ribosomes (70s) Make proteins from RNA messages CELL
MEMBRANE CYTOPLASM Slide 15 Motion Flagella Protein propeller
Attached to cell wall Use energy to move cell Not very flexible
Pili Protein filaments attached to cell wall Pulled in or pushed
out Used to adhere or stick to other bacteria cells to exchange DNA
conjugation PILI FLAGELLA Slide 16 Reproduction Binary Fission
Bacterium replicates its DNA and then divides the cytoplasm One
copy of DNA on each side Cytokinesis Slide 17 Slide 18 Identify
Prokaryotic Structures cytoplasm nucleiod Cell membrane Cell wall
ribosome Slide 19 Homework E. coli handout
