By: Jacob Pasley Dedicated to: Dr. Burke

1. Prokaryotes Play a crucial role in the biosphere (27-5)Prokaryotes have both beneficial and harmful effects on humans (27-6) By: Jacob Pasley Dedicated to: Dr. Burke

2. Prokaryotes Intro • Singled cell organism • Lack membrane bound nucleus • Two major classification domains: the bacteria and archaea • Founds in all types of habitats • Many create large colonies • Reproduce through Asexual reproduction; typically by binary fission • Involves horizontal gene transfer • transfer of genes that is not typical reproduction • Four main structures or shapes • Cocci- spherical • Bacilli- rod shaped • Spirochaete- spiral-shaped • Vibrio- comma shaped

3. Decomposers • Organism(s) that break down other organisms; they are heterotrophic • Heterotrophic- use organic substrates to get energy, carbon, and nutrients for processes and • Breaks down cells • Convert tissues into metabolically useful chemical products • No need for internal digestion; thus no technical “stomach” • Use dead organisms and non living organic compounds as a food source

4. Types of Decomposers • Bacterial/Bacteria • Can break down mostly any type of organic matter • 1 gram of soil contains 40 million bacterial cells • More bacterial than plants or animals combined; large biomass • Vital in recycling nutrients • Used in nutrient cycle(s) • Fungi • Most grow in branching network(s) of hyphae • Can penetrate large pieces of organic matter unlike bacteria • Primary decomposers in the woods • Releases enzymes that breakdowns decaying material • Hyphae is used to breakdown matter and absorb corresponding nutrients • When two fungi’s hyphae grow close to each other they fuse to form other fungi as well

5. Types of Decomposers (2) • Worms (contains slugs and snails) • Can be considered decomposers and also scavengers • A worm can remove the skin or various tissues to sped up decay • Can expose the elements or to other decomposers • Filers soil; filters out nutrients Video

6. Overall Importance of Decomposers • Decomposers help plants receive the nutrients necessary for vital life processes • Dead waster would pile up and matter would not decay • Assists with Nitrogen Fixation • where atmospheric nitrogen is filtered into organic compounds (assisted, in part, by decomposers) • Adds usable nitrogen

7. Types of Symbiosis • Three types of Symbiosis • Mutualism- both benefit • Commensalism- one benefits with little effect on the host • Parasitism- one benefits at the coast of the host • Means a relationship between 2 or more organisms

8. Symbiosis Video

9. Pathogens • (Can) produce disease • It means “Infectious Host” • Known as a microorganism (can include a virus, bacterium, prion, or fungus) • One of three P’s (predators, pathogens, and parasitoids) • Beneficial in the sense that they can serve as biological controls and suppress various (arthropod) pest populations

10. Pathogenic Prokaryotes • Prokaryotes cause ½ of human disease • This includes (famously) Lyme Disease • Types • Prior- infectious pathogens that do not include nucleic acids and abnormally folded proteins • Viral • Bacterial- often killed by antibiotics, though resistance is an issue • Fungal- usually saprophytes; common cause of disease in crops and plants • Other Parasites- such as protists and helminths • However, can be used in healthcare in vaccinations as well • Makes the immunity stay virulent against disease

11. Mutualistic Bacteria • Mutualistic relationships exist between humans and bacteria. • the human intestine and digestive systems contains up to 1,000 different species of bacteria • 10 times more abundant than the total number of cells in the human body • Benefits: bacteria can help digest (break down) food that the intestine can not efficiently digest • Bacteria in the human digestive system (and other digestive systems) also contain genes associated with nutrients, vitamins, and carbohydrates (and synthesis processes)

12. Mutualistic Bacteria (2) • Gut (intestinal bacteria) sends signals that allows humans to produce antimicrobial compounds • Probiotic- dietary supplement that contains live bacteria (ACTIVA) • Most bacteria are beneficial • Examples • Lactobacillus reuteri- protects human(s) from the effect(s) of microbes, lowers cholesterol, and assists with the immune system • Bacterial Flora- present in the human gut/ digestive system

13. Pathogenic Bacteria • Cause bacterial infection • Very few are pathogenic (infectious) • Examples • Tuberculosis- caused by Mycobacterium tuberculosis • Kills 2 million people each year • Pneumonia- caused by bacteria such as Streptococcusand Pseudomonas

14. Endotoxins • A toxin that is present in the bacteria when a cell disintegrates • Detailed by Richard Friedrich Johannes Pfeiffer • In the cell, released only after the cell wall disintegrates • Associated with lipopolysaccharide(s) and Gram-negative bacteria • Some studies show endotoxins in the digestive system can cause obesity

15. Exotoxins • Can cause damage to the host cell by destroying it or disrupting cellular metabolism • May be released during the lysis of the cell • Lysis- breaking down of the cell • Can be destroyed by heating • So toxic that it can kill the host before the immune system can respond • A toxin that is released into the environment ***Note: both endotoxins and exotoxins are ways of enducing disease

16. Prokaryotes in Research • Have led to important advances in DNA research and technology • Bioremediation • The use of these organisms to remove pollutants from the environment • Used for • Mining • Synthesis of vitamins • Production of antibiotics, hormones, and other products ***Note: just and overview: video will provide further insight