1. Chapter 27: Prokaryotes

2. What are Prokaryotes? Unicellular organisms
Inhabit almost all environments
Diverse
Categorized
Bacteria
Archaea
Microscopic
More than eukaryotes
Can inhabit very diverse habitats from volcanoes to glaceirs
Large amount of genetic diversity

3. Structures and Adaptations
Structures on the cell’s surface
Capsule
Adherence
Block harmful pathogens
Pili and Fimbraie
Cell wall
Peptidoglycan
Motility
Flagella
Internal Organization
Prokaryotic Chromosome
Circular
Nucleoid region
Adaptations
Binary Fission
Endospores
mostly unicellular
Many shapes, the most common are spheres, rods, and spirals
Mantian shape, protection, prevents bursting
Water loss inhibits reproduction
Eukaryotic cell walls are made up of cellulose or chitin
Capsule- sticky layer of protein or pollysachride, enables prokaryotes to adhere to one another (colony) or other objects
Sex pili- reproduction
Half pf prokaryotes can move in some manner
Prokaryotic flagella are not as wide and are not an extension of the plasma membrane
Less DNA
Nucleoid region- patr of the cytoplasm that appears lighter
Also have plasmids- can provide resistance to antibiotics, increase chance of survival
Reproduce quickly but it is slowed down by competition, lack of nutrients, prey
Endospores- resistant cells that are formed in presence of a lack of nutrients
Produces nutrients and tough cell wall, water is removed, metabalism is stopped, cell dies leaving the endospore behind
Endospores are durable- can stand boiling water
Prone to natural selection due to fast reproductive cycle which can results in many mutations quickly

5. Nutritional Adaptations
Photoautotroph
Photosynthetic organisms
Light energy, CO2
Cynobacteria, plants, algae
Chemoautotroph
CO2
Oxidize inorganic substances for energy
Photoheterotroph
Light energy
Carbon from organic compounds
Marine prokaryotes
Chemoheterotroph
Uses organic molecules as energy and carbon source
Prokaryotes, protists, fungi, plants, and some animals
Nutritoinal diversity id greater in prokaryotes than in eukaryotes
Chemoautotrophs- instead of using light energy they oxidize inorganic substances such as hydrogen sulfide, amonia, or ferrous ions- only found in certain prokaryotes

6. Metabolic Relationships
Cooperation
Sharing of resources
Biofilms
Oxygen
Obligate aerobes
Requires oxygen for respiration
Facultative anaerobes
Fermentation or oxygen for respiration
Obligate anaerobes
Fermentation or anaerobic respiration
Nitrogen
Amino acid and nucleic acid production
Nitrogen fixation
Obligate aerobes- cant grow without oxygen
Obligate anaerobes- poisned by oxygen
Anaerobic resperation- substances other than oxygen (nitrate ions) accept electrons in ETC- does not require oxygen
Prokaryotes can metablalize nitrogen in many forms unlike eukaryotes
Nitrogen fixation- convert nitrogen (N2) to amonia (NH3)
Metabolic cooperation- can occur between colonies
Biofilms- cells in one colony produce signaling molecules that get nearby cells- causes the colony to stop growning, produce protein to adhere to oneanother or a separate colony
Prokaryotes within species can also cooperate
Ex: on the ocean floor bacteria use the archaeas waste products while the bacteria produces products that initaite methane consumption in the archaea

8. Classification of Prokaryotes
Bacteria
Pathogens
Strep throat
Cheese
Archaea
Methanogens
Extremophiles
Extreme Thermophiles
Extreme Halophiles
Traced ancestry in prokaryotes using RNA subunits
Archaea are more closely related to eukaryotes than bacteria
Manu prokaryotes are distantly related to each other due to horizontal gene transfer (when an organizims incorporates genetic material from another organisim, without it being the original organisms offspirng)
Extremophiles- live in extreme conditions
Thermohpiles- very hot enviroments, sulfur of volcanoes at up to 90C or in deep sea hydrothermal vats at up to 113 C
Halophiles- very salty enviroments (high saline concentration), Great Salt Lake and the Dead Sea
Methanogens- obtain energy by using CO2 to oxidize H2 which releases methane as a waste product, they are posined by oxygen, live in swamps, marshes

10. Groups of Prokaryotes Spirochetes Cyanobacteria Proteobacteria
Heterotrophs
Rotate and spiral
Cyanobacteria
Photoautotrophs
Marine Ecosystems
Proteobacteria
Chemoautotrophs

11. Prokaryotic Relationships
Symbiosis
Mutualism
Commensalism
Parasitism
If all prokaryotes died tomorrow all other species would dies (unlike eukaryotes)
They recycle elements that are essential to all other life
Decomposers- break down carcuses releasing elements such as carbon and nitrogen into the atmosphere
Convert inorganix molecules in to things that can be more widely accesed by other organisms
Symbiosis0 relationships between organisms of diferent species that are in direct contact with each other
Host- larger organism
Symbiont- smaller organism
Mutalism- both organisms benefit
Commensalism- one benefits, the other is not harmed nor helped
Parasitism- the parisite benefits at the expense of the host (which is harmed)

12. Human Impact Harmful Beneficial Exotoxins Endotoxins Pathogens
Cholera
Endotoxins
Salmonella
Pathogens
Ticks, Lyme disease
Beneficial
Cheese, Yogurt
Bioremediation TB
Exotoxins- proteins made by other proteins
Cholera (diaherreal disease)- caused by an exotoxin released by vibrio cholerae, released into the gut and water (chlorine ions0
Endotoxins- only released when bacteria die, part of the outer membrane
Salmonella causes food poisisng
Bioremediaiton- use of organisms ro remove pollutants form the soil, air, or water- mining, help recover metals from the ore

13. Works Cited http://biology.about.com/od/cellanatomy/ss/prokaryotes.htm