1. Discovering the Bacterial Cell Advanced Biotechnology (c)(5)(b)

2. The Importance of Bacteria  Bacteria are extremely important in the biosphere  Food Production  Examples?  Nutrient Cycling  Such as nitrogen fixation in soil  Genetic engineering  Bacterial cells transformed  Agrobacterium-mediated recombination

3. "Nitrogen Cycle.“ http://commons.wikimedia.org/wiki/File:Nitrogen_Cycle.svg“http://commons.wikimedia.org/wiki/File:Nitrogen_Cycle.svg Nitrogen Fixation Cycle

4. Bacterial Cells  Bacterial is a large domain of prokaryotic microorganisms  Prokaryote: single-celled organisms lacking a membrane bound nucleus  Microorganism : microscopic living organisms, either single celled or multicellular  Even though bacteria are relatively simple, they boast a well-developed cellular structure responsible for their many unique functions  Organelle: subunit within a cell with a specific function.

5. Cell Morphology  Bacterial cells have different shapes. Some examples:  Coccus – spheres  Bacillus – round-ended cylinders  Spiral – twisting  Filamentous – very long thin rods, many times longer than wide

6. Coccus http://aqkhanacadmey.webs.com/photos/BIOLOGY-PRACTICAL/cocci%20bactaria.jpghttp://biology.clc.uc.edu/fankhauser/Labs/Microbiology/Buccal&Tooth/sarcinae_P7060987.jpg

7. Bacillus http://en.wikipedia.org/wiki/Bacillus#mediaviewer/File:Bacillus_species.jpg http://en.wikipedia.org/wiki/Bacillus#mediaviewer/File:Bacillus_subtilis_Gram.jpg

8. Spiral http://commons.wikimedia.org/wiki/File:ARS_Campylobacter _jejuni.jpg https://www.ebiomedia.com/images/stories/BioGalleries/Note Book/cantlivewithoutum/spirals.jpg http://sciweb.hfcc.net/biology/jacobs/bio131/cells/images/spiro100b

9. Filamentous http://www.environmentalleverage.com/filaments/slides/p_0035.jpg http://3.bp.blogspot.com/- q9p215SPAgg/T8J2T0v1ZeI/AAAAAAAAAGA/5Jxjf_pj0hQ/s1600/40X_S oilIsolate_1.JPG http://ulsfmovie.org/images/filamentous-bacteria-microthrix-parvicella.jpg

10. Bacterial Cell Structures

11.  Pili and fimbriae are interchangeable  Pili : hair-like appendage found on the surface of many bacterial.  Used for attachment to surfaces, and gene transfer Pili / Fimbriae http://www.daviddarling.info/images/pili.jpg

12.  Flagellum: leash-like appendage protruding from the body.  Primary role is movement.  Also used as a sensory organelle. Flagellum http://www.pleaseconvinceme.com/wp- content/uploads/2012/09/bacteria1.jpg

13. The ribosome is a complex molecular machine serving as the primary site of protein biosynthesis. Ribosomes Functional protein Export polypeptide to cytoplasm Link together amino acids collected from cytoplasm by tRNA Translate mRNA

14. Ribosomes

15.  Plasmids are small DNA molecules within a cell that is separate from chromosomal DNA. This makes it extrachromosomal DNA.  Plasmids carry genes benefitting survival of the cell. They carry extra information  Artificial plasmids are used as vectors in molecular cloning.  Drives the replication of recombinant DNA sequences in host organisms Plasmid

17.  Cytoplasm comprises the gel-like substance within the cell membrane and all organelles. All contents of the cell are contained in the cytoplasm. Cytoplasm http://www.learner.org/courses/essential/life/images/show1.cytoplasm.jpg

18.  The cell envelope contains the:  Capsule  Cell Wall  Plasma membrane Cell Envelope

19.  The capsule is the outer envelope of the bacterial cell. The capsule is well-organized and not easily washed off. Help prevent water loss  The capsule can be the cause of diseases, but also can play a role in the development of vaccines Capsule

20.  The cell wall of bacterial cells is a distinctive structure compared to plant and animal cells.  Cell wall made of peptidoglycan.  The cell wall has two types:  gram-positive and gram-negative.  Determined through reaction of cell walls to Gram stain.  Peptidoglycan levels play an important role in this. Cell Wall

21.  The plasma membrane is composed of a phospholipid bilayer. Acts as a permeability barrier, and location for the transport of molecules into the cell.  The phospholipid bilayer is a layer of two lipid layers that form a barrier around cells. It is found in almost all living organisms. Plasma Membrane

22.  The nucleoid contains all/most of the genetic material. It is NOT a nucleus because it is not surrounded by a nuclear membrane.  Approx. 60% DNA with small amounts of RNA and protein (later is generally mRNA and transcription factors) Nucleoid

23.  Why are bacterial cells important?  They perform activities essential for our every day survival: nutrient cycling, food production, microbial flora in our gut, etc.  What is a Prokaryote?  single-celled organisms lacking a membrane bound nucleus  What is an organelle?  subunit within a cell with a specific function. Summary

24.  Describe the following structures and their importance:  Pili / Frimbraie  Flagellum  Ribosomes  Plasmid  Cytoplasm  Cell envelope:  Cell wall  Peptidoglycan  Plasma membrane  Capsule  Nucleoid Summary: Organelles

25. Developed for the Texas Education Agency Educational Excellence for AFNR project under contract with the Department of Agricultural Leadership, Education & Communications, Texas A&M University © Texas Education Agency, 2014 Authors: Ian Sprouse, Kirk C. Edney PhD