Lecture Focus Questions; Cycles of Matter & Energy Flashcards
What are Autotrophs?
- They are capable of extracting their carbon from CO2
- They are also subdivided into Photoautotrophs & Chemolithoautotrophs
What are Heterotrophs?
- They get their carbon from organic compounds/ foods in their environment
- They are also subdivided into Photoheterotrophs & Chemoheterotrophs
What are Photoautotrophs?
-They extract energy from sunlight= photosynthesis
What are Chemolithoautotrophs
-They extract energy from the oxidation of organic compounds
What are Photoheterotrophs?
-They also get their energy from the sun
What are Chemoheterotrophs?
-They get their energy from consuming energy-rich reduced organic molecules
What is the energy flow in the biosphere?
-It is a one-way flow of energy= originates in the sun & ending up as energy loss to “waste heat”
What are Trophic Levels?
- They are the manifestation of different kinds of producers & consumers
- The energy levels are also inefficient= 10% of energy available passes through these levels while the 90% is used to keep the organisms at each level alive
What are Reservoirs?
-They are Abiotic sites that contain materials that are needed by biological systems
How does the movement from abiotic reservoirs to biotic compartments of the ecosystem occur?
-It occurs by incorporation into biological systems & is then returned abiotic when organisms die & are broken down into organic compounds by decomposers
What are the 3 types of Reservoirs?
- Water
- Air
- Sediment
What reservoir does H come from?
-It comes from H20= water reservoir
What reservoir does C come from?
- It comes from CO2= air reservoir
What reservoir does O come from?
-It can come from H2O or CO2= water or air reservoir
What reservoir does S and P come from?
-Sediment reservoir
What is the Carbon Cycle?
- It involves carbon atoms in the form of CO2 leaving the atmospheric reservoir & being incorporated into producers which passes it on to consumers
- Carbon is then returned to the atmosphere as CO2 by the producers & consumers
Why has allowed the Carbon cycle to stay in balance?
-It stayed in balance bc of the opposing processes of photosynthesis & respiration
What is a Greenhouse Gas?
-It is a gas that traps radiant energy from the sun as heat
What are the 2 most powerful greenhouse gasses?
- Carbon dioxide
- Methane
What are Fossil Fuels?
-They are fuels like coal, oil. and gas that have been derived originally from biological processes
What is the evidence for increased concentration of CO2 in the atmosphere?
- The keeling curve= measured at a remote location in Hawaii for the last 60 years
- The curve shows a smooth increase in CO2 from 315ppm in 1960 to over 415ppm now
What is the evidence that increased CO2 is due to burning Fossil Fuels?
- The evidence is via isotope analysis
- The ratio of C12 & C13 has been increasing BUT the decrease of C14 says that the source fo the increase of CO2 is due to fossil fuels
What 3 processes might have led to natural cooling of the Earth’s climate during earlier times?
- The oxidation of methane to CO2
- Volcanic activity that ejected ash & sulfur oxides into the atmosphere (reflects sunlight)
- The incorporation of more atmospheric CO2 into the biomass of newly evolved organisms during the time of plant growth=jurassic
What process might have led to the natural warming of the Earth’s climate during earlier times?
-The increased volcanic activity that ejected CO2 into the atmosphere
What is the relationship between C,H & O in terms of the cycling matter in the biosphere?
- Photosynthesis & respiration control the carbon cycle & brings H & O in & out biological systems
- SO photosynthesis uses water as the source of electrons & H atoms to make reduced C compounds & releases O2
- While O2 is used for respiration by both consumers & producers
