Physical Perspectives (1,3,5)

what are the biogeochemical cycles?
carbon cycle, nitrogen cycle, phosphorus cycle, sulfur cycle, hydrologic cycle
define biogeochemical cycles
process by which matter cycles from the living world to the nonliving physical environment and back again
define photosynthesis
biological process that captures light energy and transforms it into chemical energy of organic molecules (glucose) manufactured from carbon dioxide and water
define carbon cycle
global movement of carbon between organisms and the abiotic environment
what is photosynthesis’ relation to the carbon cycle?
during photosynthesis, plants remove carbon from the air and fix it into chemical compounds such as sugar.
what is cellular respiration’s relation to the carbon cycle?
cellular respiration returns C02 to the atmosphere
What is the relation of fossil fuels and sedimentary rocks to the carbon cycle?
Sedimentary rocks and fossil fules hodl almost all of Earth’s estimated 10^23 g of carbon. the carbon in them can return to the atmosphere by burning, or combustion
Why is Nitrogen crucial for all organisms?
Nitrogen is an essential part of biological molecules such as proteins and nucleic acids (DNA)
What is the first step of the nitrogen cycle?
nitrogen fixation (conversion of gaseous nitrogen to ammonia, fixed into a form that organisms can use)
What processes enable nitrogen fixation?
Combustion, lightning, industrial processes… bacteria
What is the second step of the nitrogen cycle?
Nitrification
What occurs during Nitrification?
ammonia or ammonium is converted to nitrite or nitrate, and the soil bacteria are furnished with energy
What is the third step of the Nitrogen cycle?
Assimilation
What occurs during assimilation?
plant roots absorb nitrate, ammonia, or ammonium and incorporate the nitrogen from them into plant porteins and nucleic acids. animals consume plant tissues, they convert the nitrogen into animal proteins
What is the fourth step in the nitrogen cycle?
ammonification
What occurs during ammonification?
organisms produce nitrogen waste products such as urine…this combined with nitrogen in dead organisms are decomposed by bacteria to produce ammonia, which re-enters the cycle
What is the fifth step in the Nitrogen cycle?
Dentrification
What occurs during dentrification?
nitrate is reduced to gaseous nitrogen by bacteria, which is released into the atmosphere. these bacteria live where there is no oxygen, deep in the water table
What is the phosphorous cycle?
The global circulation of phosphorus from the environment to living organisms and back to the environment
What occurs during the phosphorous cycle?
phosphorous cycles from the land to sediments in the ocean and back to the land
What are the steps of occurence of the phosphorus cycle?
phosphorus erodes from rock as inorganic phosphates and plants absorb it from the soil. animals obtain phosphorus from their diets, and decomposers release inorganic phosphate into the environment
What is the sulfur cycle?
the global circulation of sulfur from the environment to living organisms and back to the environment
Where is most sulfur located?
underground in sedimentary rocks and minerals (second largest supply=ocean)
What is the relationship between the Sulfur cycle and the atmosphere?
sulfur gases enter the atmosphere from natural sources in the ocean and land (sea spray, forest fires and dust storms), sulfur is a minor part of the atmosphere because it doesn’t stay long, but the overall movement back and forth is substantial
What is phosphorus used for biologically
nucleic acid and ATP (energy transfer reactions in cells)
What is nitrogen used for biologically
protein and nucleic acids (DNA)
What is carbon used for biologically
composes proteins, carbs, and other molecules
What is sulfur used for biologically?
Tiny amount present in living organisms, but essential component of proteins
What is DMS?
Dimethyl sulfide, a compound released by algae that is released into the atmosphere and condenses water into clouds and may affect weather and climate
What is the hydrolic cycle?
The global circulation of water from the environment to living organisms and back to the environment
What results from the hydrolic cycle?
a balance between water in the ocean, the land, and in the atmosphere.
What is transpiration?
the loss of water vapor from land plants, adds water to the atmosphere
What is an estuary
where fresh water meets the ocean
what is runoff?
the movement of water from land to rivers, lakes, wetlands, and ultimately the ocean
what is a watershed?
the area of land drained by runoff
What is groundwater?
fresh water stored in underground caverns and porous layres of rock
ecology vs. environmental science vs. environmentalism
ecology= study of systems including relationships among organisms, as well as organisms and their environment… environmental science=how humanity interacts with other organisms and the nonliving physical environment;;; environmentalism=helping to solve environmental problems
why is environmental studies a crisis discipline?
a crisis discipline is when we must act before knowing all the facts; solutions to environmental problems are often adopted without complete information
basic vs. applied science
basic science: gaining knowledge, develop better understanding… applied science: solve problems
What is energy?
the ability to do work (carried out when an object is moved against an opposing force)
what is the first law of thermodynamics?
energy cannot be created or destroyed but it can be transformed
what is the second law of thermodynamics
usable energy decreases over time, disorder increases
What is the difference between how plants vs. animals aquire energy?
Animals are heterotrophs (consumers of food), plants are autotrophs (producers of food)
Describe the autotrophic nature of plants
plants produce organic matter from inorganic molecules
Define organic
carbon based (sugars, proteins)