Energy, energy cycles, organism organization Flashcards
the ability to do work (including heating)
energy
Forms of energy
Kinetic energy and potential energy
Energy due to motion
Kinetic energy
thermal energy
microscale
rigid body motion
macroscale
Energy that is stored, and may eventually be released
potential energy
chemical energy
microscale
gravitational energy
macroscale
study of how energy is transferred
Thermodynamics
energy is conserved, neither created nor destroyed, can only be recycled
1st law
each energy transfer reduces the amount of energy available to do work
2nd law
Entropy (i.e., chaos/disorder)
tends to increase in all natural systems so, we need a constant input of energy to maintain life.
Main transfer processes
work and heat
applying a force over a certain distance
work
energy transferred between objects of different temperature
heat
capturing energy from sun, air, and water
photosynthesis
energy sources
solar and chemical energy
Performed by primary producers/plants
How much energy? 1,372 joules per second per square meter
½ reflected/absorbed by clouds, dust, gases
½ that reaches us – 10% UV, 45% visible, 45% IR
Most absorbed by land/water or reflected into space
Only 1–2% of sunlight that reaches plants used for photosynthesis
photosynthesis
capturing energy from inorganic compounds (e.g., deep sea bacteria)
Chemosynthesis
Water molecules are split, oxygen is released
Source of nearly all oxygen in the atmosphere
Source of many complex organic molecules
photosynthesis
fuel is decomposed to release energy
Carbon and hydrogen are split from sugar molecules
Combined with oxygen to recreate carbon dioxide and water
cellular respiration
Most water stored in oceans, but cycles throughout planet via evaporation, precipitation, and percolation
Human impacts - pollution
hydrologic cycle
Photosynthesis and cellular respiration, sedimentation and fossil fuel burning
Human impact – shortening residence time of carbon in carbon sinks (sedimentary deposits, forests), increasing net atmospheric CO2
carbon cycle
Nitrogen fixing and bacterial decomposition is key
Human impact – synthetic fertilizers, nitrogen-fixing crops, fossil fuel burning more nitrogen than land can process
Eutrophication of water (nutrient overloading explosion of plant live oxygen consumption during decay)
acidification of water
Increase in atmospheric N2O
nitrogen cycle
No atmospheric component
Sedimentation and erosion based, very slow
Human impacts – increased mining for use in fertilizers, detergents
Runoff into water - eutrophication
phosphorous cycle
Most stored in rocks and minerals
Released via weathering, deep sea vents, and volcanic eruptions
Human impacts – decreased residence time via fossil fuel extraction and burning
Increased atmospheric sulfuric acid leads to acid rain
Sulfur dioxide can cause health and vegetation damage but also might offset GHGs by providing cloud cover, thus increasing Earth’s reflectivity
sulfur cycle
organisms of the same kind
species
all members of a species living in a given area at the same time
population
all populations living and interacting in a given area
biological community
biological community and its physical environment; productivity – amount of biomass produced in an area in a given time
ecosystem
feeding status of an organism
trophic level
Energy transfer between trophic levels
General rule – 10% moves from one level to the next
feeding categories
Autotrophs Herbivores Carnivores Omnivores Scavengers Detritivores Decomposer
individual chain of who eats whom in an ecosystem
food chain
multiple food chains interconnected
food webs
illustrates how energy moves through a ecosystem
ecological pyramid
