Homeostasis - metabolism

All of these nutritional modes are found among Bacteria!No other kingdom is as diverse in its metabolic pathways.

Nutrition ModeEnergy Source

Carbon Source

Photoautotroph Light CO2

ChemoautotrophInorganic

chemCO2

Photoheterotroph

LightOrganic chem

Chemoheterotroph

Organic chemOrganic chem

Photoautotrophs - photosynthesis

• Ancient pathway, but not universal

• Cyanobacteria, Algae, Plantslight

CO2 + H2O O2 + CH2Ochlorophyll

• Purple-sulfur bacterialight

CO2 + H2S Ss + CH2Ochlorophyll

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http://www.plantmorphogenesis.bio.titech.ac.jp/images/Chloroplast%20Photo.jpg

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http://faculty.uca.edu/~johnc/Chloroplast_and_microbodies.jpg

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http://www.jgi.doe.gov/JGI_microbial/images/microbes2003/anava.jpg

Chemoautotrophs - N metabolism

• Cyanobacteria, Rhizobium - N2 fixation

H+ + ATP + N2 NH4+

• Nitrosomonas - nitrificationCO2 + NH4

+ NO2- + CH2O

• Pseudomonas - denitrificationCH2O + NO3

- N2 + CO2 + H2OWhich of these processes is demonstratingchemoautotrophism?

√

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http://soils.usda.gov/sqi/soil_quality/soil_biology/images/Nods_on_beans_LR.jpg

Photoheterotrophs - strange

• Rhodospirillum, Rhodomicrobium Light

C2H4O2- + H2O O2 + CH2O

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http://www.acadweb.wwu.edu/courses/envr429-rm/Robin/images/envr429/1_rhodospirillum_600x.jpg

Chemoheterotrophs - strange

• Escherichia coli and many others!

CH2O + O2 CO2 + H2O

Carbohydrate, etc. provides boththe energy source

andthe carbon source

What is another chemoheterotrophic organism?

Give the complete Latin binomial!

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http://www.up.ac.za/academic/electron/mito1.htm

Plant mitochondrion

cristae(mesosomes)

outer membraneinner membrane

Chemoheterotrophy• Aerobic Respiration

– Glycolysis carbohydrate to pyruvate– Citric Acid Cycle pyruvate to carbon dioxide– Electron Transport Oxidative Phosphorylation

CH2O + O2 CO2 + H2O• Anaerobic Fermentation

– Glycolysis to pyruvate– Fermentive step(s) to return NAD+ to glycolysis

C6H12O6 C3H3O3- C2H5OH + CO2

C6H12O6 C3H3O3- H3CCHOHCOO-

Notice how fermentation can produce gas or acids…These are just a few of the fermentive possibilities!