Prokaryotes and the Origins of Metabolic Diversity

Classification Kingdom: Monera? Domain: Bacteria Domain: Archaea Shape •cocci (sphere) •bacilli (rod) •helical (spiral)

Structural characteristics Cell wall~ peptidoglycan (sugars & proteins); √ Gram +: w/peptidoglycan penicillin action √ Gram -: little peptidoglycan, lipopolysaccharides; most pathogens; impede drug action Capsule: adherence; protection Pili: adherence; conjugation

Motility 1- Flagella 2- Helical shape (spirochetes) 3- Slime 4-Taxis (movement away or toward a stimulus)

Form & Function Nucleoid region (genophore: non-eukaryotic chromosome) Plasmids Asexual reproduction: binary fission (not mitosis) “Endospore: resistant cells for harsh conditions (250 million years!)

Form and function cont. “Sexual” reproduction (not meiosis): transformation~ uptake of genes from surrounding environment conjugation~ direct gene transfer from 1 prokaryote to another transduction~ gene transfer by viruses

Nutrition & Metabolism Photoautotrophs: photosynthetic; harness light to drive the synthesis of organics (cyanobacteria) Chemoautotrophs: oxidation of inorganics for energy; get carbon from CO2 Photoheterotrophs: use light to generate ATP but get carbon in an organic form

Black smoker – Sulfur (hydrogen sulfide) or Iron http://www.youtube.com/watch?v=BXGF3XS-yAI Black smoker – Sulfur (hydrogen sulfide) or Iron White smoker – barium, calcium, silicon and CO2 http://www.youtube.com/watch?v=huTJlHMR_LE&list=PL84B4C76ABEFABB07 http://www.youtube.com/watch?v=D69hGvCsWgA Water temp can approach 400oC

Chemoheterotrophs: consume organic molecules for both energy and carbon saprobes- dead organic matter decomposers parasites- absorb nutrients from living hosts Nitrogen fixation: conversion of atmospheric nitrogen (N2) to ammonium (NH4+) Oxygen relationships: obligate aerobes; facultative anaerobes; obligate anaerobes

Nitrogen Fixers (“fixing” the nitrogen so we can use it)  Plants and animals depend on bacteria for nitrogen. You may recall that plants need nitrogen to make amino acids, the building blocks of proteins. Nitrogen gas (N2) makes up approximately 80 percent of Earth's atmosphere. However, plants cannot use nitrogen gas directly. Nitrogen must first be changed chemically to ammonia (NH3) or nitrates (NO3) and other nitrogen compounds. And this is where bacteria come in

Many plants have symbiotic relationships with nitrogen-fixing bacteria. For example, soybeans have nodules on their roots where bacteria “live”, converting nitrogen gas to usable nitrogen products. Biologists continue to discover new uses for bacteria – especially in the field of biotechnology.

http://studyjams. scholastic http://studyjams.scholastic.com/studyjams/jams/science/ecosystems/nitrogen-cycle.htm

(Anabaena, Nostoe, Aulosira, Tolypothrix) pick up atmospheric nitrogen reducing it to the level of ammonia. It adds 140-700 mg/m2/yr of nitrogen.

Prokaryotic ecology Decomposers: unlock organics from corpses and waste products Symbiosis~ •symbiont/host •mutualism (+, +) •parasitism (+, -) •commensalism (+, 0)

Disease •opportunistic: normal residents of host; cause illness when defenses are weakened •exotoxins: bacterial proteins that can produce disease w/o the prokaryote present (botulism) •endotoxins: components of gram - membranes (Salmonella)

French chemist Louis Pasteur German bacteriologist Robert Koch Kochs postulate; 1st - identify a symptom; 2nd – isolate an organism from the victim; 3rd – inoculate the organism in a test animal; 4th – re-isolate the organism. Steere and his colleagues were able to link the skin rash to the bite of the tiny deer tick (Ixodes scapularis). One of Steere's colleagues, Dr. Willy Burgdorfer, found an unusual spiral-shaped bacterium (Borrelia burgdorferi) in the ticks. Steere found the same bacterium in patients with Lyme disease. Could this bacterium be the cause of Lyme disease?

I’m not sure if you know much about tetanus but it’s near the top of my “ways I don’t want to die” list. Tetanus is everywhere. It’s a bacteria that grows in the dirt. We cannot get rid of it. What does it do to you? It slowly makes all the muscles in your body contract and not release until your heart stops beating or you can no longer breathe.

Many bacteria live on and within our bodies, and some bacteria even help us to perform essential functions, such as digesting our food. The growth of pathogenic bacteria, on the other hand, disrupts the body's equilibrium by interfering with its normal activities and producing disease. Clostridium perfringens Also implicated in food poisoning

Rusty Wagstaff doesn’t remember anything between Dec Rusty Wagstaff doesn’t remember anything between Dec. 18, when he first showed the symptoms of influenza, and Jan. 4, when he awoke in the hospital with no legs and was told his hands needed to be amputated.