Atom – Molecule – Cell – Tissue – Organ – Organ System – Organism – Polpulation – Community – Ecosystem – Biosphere
Autotrophs – Herbivores – Carnivores – Top Carnivores
Microorganisms beneficial roles: - Marine and freshwater microorganisms are at the base of food chains - Perform photosynthesis (cyanobacteria and algae): which generates biomass and produce oxygen - Decomposer: break down organic molecules and recycle chemical elements between soil, water, living organisms and air - Fix N2 into NH4 (Nitrogen fixation: bacteria in plant nodule and Cyanobacteria) - Convert NH4 back to N2 (denitrification: denitrifying bacteria) - Break down waste and toxic compound
FIRST TROPHIC LEVEL: - Photosynthesizers or primary producers: are autotrophs that get their energy directly from sunlight and covert it into chemical energy of the organic compounds that they produce: biomass - Light + 6 CO2 + 6 H2O = C6H12O6 + 6 O2
Who are the primary producers? - Photosynthetic Bacteria (like Cianobacteria) - Photosynthetic Protists: Phytoplankton, inlcuding algae like diatoms - All land plants perform PHOTOSYNTHESIS: the process by which solar energy is transformed into Biomass They are PRODUCERS: at the base of Earth’s food chains
Atmosphere - A thin layer of gases surround Earth; 78% N2 21% O2, 1% argon, .03% CO2, traces of xenon, helium and ozone - The CO2 is the source of carbon used by producers to produce Earth’s biomass - Bacteria recycle Carbon, Nitrogen, Sulfur, Phosphorus and other nutrients that can be used by plants and animals
Nitrogen cycle - N2 gas makes up 78% of the atmosphere, but most organisms cannot use N in this form. - Some bacteria can fix N2 into a form usable by plants (NH4 – NO2- - NO3-): - Nitrogen fixing bacteria; nitrite bacteria; nitrate bacteria - Other bacteria can convert NO3- back into N2, (denitrifying bacteria), returning N2 to the atmosphere.
Bioremediation
- Bacteria degrade organic matter in sewage - Bacteria degrade or detoxify pollutants such as oil and mercury
What is oil? - Remains of zooplankton and algae - Formed under extreme heat and pressure - Most petroleum has been biodegraded over time
Many microorganisms participate in mutualistic interactions with other type of organisms: - plants and N-fixing bacteria (root nodules) - plants and mycorrhizae (associated fungi that help in absorbing water and soil minerals) - lichens: fungi with endosymbiontic photosynthetic algae - corals (animals) and photosynthetic algae - termites/herbivores harbor bacteria in their guts that digest cellulose - bacteria residing in human and other animal intestine (help in food digestion and provide us with essential vitamins like Vitamin B and Vitamin K)
Cellulose-digesting bacteria are found in all grazing animals such cow, horses, etc… - Cellulose is the main component of plant material in herbivore diet - Herbivore and termites can digest cellulose because they harbor cellulose-digesting bacteria in their digestive tract
Microorganisms beneficial roles: Commercially used to produce: - Vitamins - Organic acids - Enzymes - Alcohols, Methane, … - Many drugs - Foods: yogurt, cheese, beer, bread, soy sauce, pickles, sauerkraut, vinegar, etc…
Genetically engineered to produce: - Cellulose - Digestive aids - Drain cleaner - Therapeutic substances like insulin… - Many drugs - Plastic-like materials - Biological Insecticides - Fuel (ethanol) from crop (cellulose): - Engineered bacteria to break down cellulose into
