1. By: Jacob Pasley Dedicated to: Dr. Burke
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 Fungi
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 Examples
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 Streptococcus and 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