Chapter_3_Internal_slides.pdf

Prokaryotic Structures (Internal) Chapter 3 Bacterial Anatomy Overview Cell envelope  hardwire-chromosome Nucleoid and Plasmid bound Nucleoid...

Prokaryotic Structures (Internal) Chapter 3 Bacterial Anatomy Overview Cell envelope  hardwire-chromosome Nucleoid and Plasmid bound Nucleoid -not membrane – Dense area within the cell where the DNA aggregates – NOT a nucleus! Plasmid : not found in all bacteria + come and go not unique to just bacteria (ex fungi – Extrachromosomal pieces of DNA – Not essential to bacterial growth and metabolism (no essential genes. Pilus can share - the plasmid and Da is in one disappears once it is done. single circular Piece of chromosome Can a bacterial cell with only plasmids and no -cytoplasm chromosome survive? (no : Plasmids are super powers ! chromosomes = genetic blueprint & Y  Why carry around that extra DNA? CAPSULE STAIN Plasmids may carry: · genes for antibiotic resistance · genes for producing toxins and enzymes (harmful to us) Cast resort for gram() infections. CDC CRE Tracking Maps resistances to carbapenem due to plasmid  Ribosomes (prokaryotic) Structure – Ribosomal RNA (rRNA) and proteins Function bacterial ribosomes * protein synthesis are different than evk. ribosomes different target - treatment 30S 50S 70S Density S * bacteria 2 70s = eukaryotes = 80s  Inclusions * Structure – Non-membrane bound granules Function Magnetotactic bacteria contain particles of iron oxide (yellow objects)  Bacterial Hibernation Endospore structure made by some bacteria but NOT bacteria. ~ no metabolism no cells Call ,. - Dormant, tough, non-reproductive bodies. ' meaning Resistant to heat, radiation, and disinfectant chemicals! Sporulation (production of endospores) occurs - 11 due to nutrient depletion Endospores contain genetic Structure of an endospore - 9/30/2018 Bacterial Endospores | Department of Microbiolog material along with ribosomes and enzymes needed to return to vegetative stage Bacillus and Clostridium Sporulation Cycle * do not need to memorize - vegetative state -D↓ endospore % D starts in a forming nutrient depleted environment b & ⑨ ⑨ b b & cangerminate enterial e D cell. Sporulation video Endospores Under the Microscope Endospore Stain Are endospores bacterial cells? Inoi endospores are dormant bodies produced by certain bacteria Red = vegetative cells Green = endospores  Vegetative cells vs. Endospore Vegetative cell Endospore Metabolically active Yes No Reproduces Yes No Resistant to heat, No Yes radiation, & chemicals Lifespan Normal Indefinite Which clinically significant Vegetative cell bacterial genera produce endospores? Bacillus and Clostridium Endospore 'B sub. IC Diff. What role do endospores play in infectious diseases? Other Endospore Producers Clostridium tetnai tetanus Clostridium botulinum By Herbert L. Fred, MD and Hendrik A. van Dijk - http://cnx.org/content/m14960/latest/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=11893642  Review: Parts of a Bacterium External Structures Internal Structures 1. S layer 1. Nucleoid 2. Glycocalyx 2. Plasmid 3. Flagella/ Axial 3. Ribosomes filaments 4. Inclusions 4. Fimbriae 5. Endospores Cell Membrane 5. Pili Cell Wall Which structures do ALL bacteria possess? Which structures are optional? After successfully completing this learning unit, you will be able to: 1. Describe the nucleoid and the plasmid. 2. Compare and contrast the function of the nucleoid and the plasmid. 3. Describe the structure and function of prokaryotic ribosomes. 4. Describe the structure and function of inclusions. 5. Describe the structure (brief) and function an endospore. 6. Compare and contrast an endospore and a vegetative cell. 7. Explain the clinical significance of endospores.