Chapter 3 and 7 Flashcards
Mid-term study
What kind of radiation is Earth absorbing from the sun?
mostly short wave; input as electromagnetic radiation
What kind of radiation does the Earth emit back?
mostly long wave
electromagnetic radiation equation
E= hv; where E= energy of quantum,
* h=Planck’s constant = 6.6x10–34 Js,
* υ = frequency s–1
How much radiation does the earth get from the sun as input?
Only 0.002% of total radiation emitted from sun forms input to earth
What is an ideal radiator?
shortwave length, high quality; solar radiation (black body)
What is the solar constant?
1370 W m–2
What does a short wavelength mean for wavelength?
shorter the wavelength the higher the frequency of ultraviolet radiation
What is a black body radiator dependent on?
on temperature of the object that is emitting; the hotter the temperature, the shorter the wavelength and higher the frequency
How does solar radiation change throughout the year?
radiation is not even throughout the year, varies seasonally: we are closest to the sun during the winter and further from the sun during the summer therefore this varies spatially and temporally
Thermal radiation relations
-stefan boltzmann’s law
-wavelength-frequency relationship
-wien’s displacement law
Stefan Boltzmann’s Law
describes the intensity of the thermal radiation emitted by matter in terms of that matter’s temperature
I=σT4
* where σ=5.67x10–8 Wm–2K–4, K = degrees Kelvin
Wavelength-frequency relationship
λ=c/υ
* where λ=wavelength, c=velocity of light, υ = frequency s–1)
Wien’s Displacement Law
states that the black-body radiation curve for different temperatures will peak at different wavelengths that are inversely proportional to the temperature.; emission
λm=w/T
* where λm=wavelength of maximum emission, w=Wien’s constants = 2.897 x 10–3 mK,
T=absolute temperature
Do earth and sun radiate at different wavelengths
yes; sun: short-wave (mostly visible); earth: long-wave (mostly infrared)
Without the atmosphere what is the long term balance net radiation?
net radiation = incoming radiation (mainly shortwave)
minus
outgoing radiation (mainly longwave)
= 0
Farenheit vs Celsius vs Kelvin
Water boils: 212F, 100C, 373K
Water freezes: 32F, 0C, 273K
Absolute O= -459F; -273C, 0K
Why does the sun and earth have different wavelengths?
The temperature of each is quite different; sun= 6000K; Earth: 59F~15C~288K
How does earth release energy?
through earthquakes, uplift (mountain formation) and formation of volcanoes
How do greenhouse gases work?
reradiation: The atmosphere allows most of the visible light from the Sun to pass through and reach Earth’s surface. As Earth’s surface is heated by sunlight, it radiates part of this energy back toward space as infrared radiation. This radiation, unlike visible light, tends to be absorbed by the greenhouse gases in the atmosphere, raising its temperature. The heated atmosphere in turn radiates infrared radiation back toward Earth’s surface.
atmosphere allows most solar
radiation to pass through it, but inhibits the passage
of terrestrial radiation
Radiation balance of the earth’s surface
Q= K+L
Does earth get more radiation from the atmosphere or the sun?
the atmosphere
radiation balance of the atmosphere
- QA=KA+LEA–LA–L
- KA (short wave from solar beam) = 17
- LEA (long wave from terrestrial radiation) = 91
- LA (long wave to space) = 57
- L (long wave back to earth) = 78
- Net radiation balance of –27
boundary of the atmosphere is both__
giving and receiving 100 units and its balance is 0
alternative energy exchange
-only considers radiant energy from sun and earth
How does annual and diurnal net radiation change in warm and cold?
- When negative there is cooling
- When positive there is warming
Conduction
the process of transferring energy, such as heat or electricity, from one object to another through direct contact
energy is transferred by direct contact
convection
-a heat transfer process that occurs due to the movement of a heated fluid; transfer of internal energy into or out of an object by the physical movement of a surrounding fluid
energy is transferred by the mass motion of molecules
Drives the global circulation
of the air and water, moves
energy from the surface back
to the atmosphere
radiation
energy is transferred by electromagnetic radiation
What are sources of the earth’s internal energy?
- Small bodies arriving at the surface kinetic energy and
compression - Gravitational pressure
- Isotope decay
What are the four spheres? Why are they important?
atmosphere, biosphere, hydrosphere, lithosphere; all have functional links involving transfers of energy and matter with the living material of the biosphere
What is the simplest independent structure of organization that possesses all the properties neccessary for life?
the cell
What is discrete life?
basic properties that keep it alive: able to reproduce, replicate and repair itself
Reductionist approach to life
-model biosphere at the cellular level – reduce cell to its constituent parts
-the chemistry of life is not just a reflection of the chemistry of the environment
-accepted/rejected some elements
-hydrogen, oxygen and carbon are the most important elements of life
-atmosphere is mostly nitrogen and oxygen
-What effect has this differential selection had on the elemental composition of the atmosphere, hydrosphere and lithosphere? Elements have been moved around as we have needed them and used them
Life vs nonlife
-living systems are subject to the same physical and chemical laws that govern non-living systems
-simple and complex molecules: monomers: fatty acids, simple sugars, mononucleotides, amino acids… and polymers
What are the 3 kinds of work?
-chemical work: maintenance and growth (biosynthesis)
-transport work: building gradients (relative concentrations)
-mechanical work: contractile filaments
-all involve endergonic or energetically uphill processes; energy demanding
endergonic reaction
energy is absorbed
exergonic reaction
releases energy
What is the molecular currency?
ATP= adenosine triphosphate
What does ATP do?
able to store and transport chemical energy within cells
What does glycolysis produce?
2 ATP, 2 NADH, and 2 pyruvate molecule without oxygen
What is glycolisis?
a metabolic process at the start of the chain of reactions within the process of cellular respiration – production of cellular energy. It occurs in the presence or absence of oxygen to enable aerobic and anaerobic cellular respiration. The glycolysis pathway converts one glucose (sugar) molecule into two pyruvate molecules; this ten-step conversion occurs in the presence of specific enzymes in the cell cytosol
When glycolysis occurs, a glucose molecule (C6H12O6) is turned into two pyruvate (CH3(C=O)COOH) molecules and one positively-charged hydrogen ion (H+). This reaction requires other ingredients – two positively-charged oxidized NAD+ (nicotinamide adenine dinucleotide) coenzyme molecules, two inorganic phosphate molecules, and two adenosine diphosphate (ADP) molecules.
C6H12O6 + 2 NAD+ + 2 Pi + 2 ADP
A ten-step process eventually converts glucose into two pyruvate molecules, two water molecules, two adenosine triphosphate (ATP) molecules, two reduced nicotinamide adenine dinucleotide (NADH) molecules, and two hydrogen ions.
Where does glycolysis take place?
in the cytoplasm of eukaryotic and prokaryotic cells
What is cellular respiration?
the process through which cells convert sugars into energy. To create ATP and other forms of energy to power cellular reactions, cells require fuel and an electron acceptor which drives the chemical process of turning energy into a useable form.
Aerobic respiration uses oxygen – the most powerful electron acceptor available in nature.
- Respiration converts chemical
energy in glucose bonds to
recharge ADP into ATP - 1 glucose molecule can produce
38 ATP molecules
OHCOOOHC 2226126 666
Not 100% efficient: heat lost is known as respiratory or
catabolic heat loss.
Where does cellular respiration take place?
mitochondria
ATP vs ADP compared as a battery
ATP as fully charged molecular battery; ADP as exhausted, discharged battery
steady state definition
when energy input = energy output maintaining a constant temperature
What is the steady state of a cell?
- Cell is constantly being rebuilt over and over again
- Systems that posses relatively low entropy compared to
environment around them - Species have evolved from lower primitive to higher, more
complex forms. - The biosphere as a whole has progressively decreased its internal
entropy as it has increased in diversity - Second Law would suggest the opposite
-cell is able to build complex structures and carry out complex functions by diverting part of the downhill thermodynamic trend into uphill energy-demanding processes by means of several chemical reactions
-does this at the expense of the surroundings which gain entropy. Total entropy of system + surroundings increases in accordance with second law
-sustainable systems are based on this throughflow
-cells and living systems are open systems
-the steady state is the orderly state of an open system; steady state= inputs= outputs (both are balanced)
is the biosphere devouring itself? (heterotrophic cell)
depends on the rate that we are taking in energy
Autotrophic cell
Autotrophic cell can produce organic fuel molecules (usually carbohydrates)
from inorganic molecules using some external source of energy
* Photosynthesis a reversal of respiration
* ADP is converted to ATP, which donates energy to build carbohydrates
* Chlorophyll absorbs in the red and blue wavelengths it reflects green.
* Light phase – photon hits chlorophyll which donates an electron to a series
that generates ATP (does not require oxygen)
* Dark Phase – synthesis of organic carbon compounds to store energy
Photosynthesis
the biochemical pathway which converts the energy of light into the bonds of glucose molecules. The process of photosynthesis occurs in two steps. In the first step, energy from light is stored in the bonds of adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). These two energy-storing cofactors are then used in the second step of photosynthesis to produce organic molecules by combining carbon molecules derived from carbon dioxide (CO2). The second step of photosynthesis is known as the Calvin Cycle. These organic molecules can then be used by mitochondria to produce ATP, or they can be combined to form glucose, sucrose, and other carbohydrates. The chemical equation for the entire process can be seen below.
Photosynthesis equation
6 CO2 + 6 H2O + Light -> C6H12O6 + 6 O2 + 6 H2O
Why are plants green?
They contain the pigment chlorophyll, which absorbs blue and red light for photosynthesis.
Chlorophyll reflects green light, giving plants their green color.
Individual is a discrete living system that is in __
direct contact with its
non-living environment
-animals have their own energy, they absorb energy from the sun, ground, tree, etc.
-estimates there are ~8.7 million species of animals
Evolution
- Heritable variation in the population of that species
- Random variation in the environment (nonrandom variation)
- Environmental sieving of genotypes – selection of adaptive variation
in the population - Darwin’s process of natural selection ultimately leads to speciation
either abruptly or gradually - Endemic species – reduced in distribution
- Cosmopolitan species – present in almost all the world’s land masses
What is an endemic species?
Is any species or other taxon whose geographic range or distribution is confined to a single given area.
May inhabit a very small area or its range may extend across an entire continent.
Is considered endemic if it is not found anywhere else in the world.
Occurs in only one location and is important to the ecosystems in which it lives.
What is a cosmopolitan species?
universally distributed species is one that can be found almost anywhere in the world. This means they have a wide geographical distribution. The fact that a species is cosmopolitan does not mean that we are going to find it in every corner of the planet.
Consequences of Niche Construction
1-ecosystem engineering
2-organisms modify their own and others’ selective environments
3-organisms create an ecological inheritance
4-adaptation depends on both natural selection and niche construction
Implications of Niche Construction
5) For evolution: genes can interact via the external environment. A second role for phenotypes in
evolution
6) For ecology: organisms can co-evolve by modifying their environment. Promotes a closer
integration of ecosystem ecology and evolution
7) For humans: a new evolutionary framework for the human sciences.
What is ecological inheritance?
: animals are changing/modifying their environment so that they are able to be more successful and are sending this environment to their offspring ; Envirotype and genotype
the persistence of environmental modifications by a species over multiple generations to influence the evolution of that or other species.”
net primary productivity
net accumulation of energy over the period of time (change of biomass); has to do with plants (change of biomass)
net secondary productivity
for heterotrophic levels also called conversion
Productivity is rate of change in energy content of the trophic level
refers to the increase in energy or biomass produced by consumers; it is the rate of organic matter not used by heterotrophes or consumers
What are the biogeochemical cycles that transfer energy through the ecosystem?
carbon, phosporus, nitrogen, water, oxygen
Phosphorus cycle
-phosphate is a rock that comes up in the weathering processes
-plants need phosphorus (ADP; DNA); we eat these plants and take their phosphorus; plants and animals die and release the phosphorus into the environment again
-over the long term phosphorus is lost through runoff into water and is buried through sedimentation
-fertilizers are mostly made of phosphorus and they add so much that there is an excessive amount of it placed into the system
-wastewater is also full of phosphorus from human activity
-detergents are made of phosphorus
-excess phosphorus leads to eutrophication
-our phosphorus comes from mining from stones; Bone Valley, Florida
-non renewable resource; hard to accumulate it
-bird guano is high in phosphorus
-found in soil, water, life; not in the atmosphere
Nitrogen cycle
-starts in the atmosphere, changes forms a lot
-nitrogen in the atmosphere is nonreactive; N2 (meaning it is stable and not available to life)
-nitrogen fixation converts N2 to “biologically available nitrogen” – bacteria (free living in soils or living with legume plants) release this which can be assimilated by the plants which are eaten by animals. The animals die and release it into the environment etc
-denitrification: turns biologically available nitrogen into elemental nitrogen (N2) done by different bacteria, sending it back into the atmosphere as N2
-lightning can break apart N2 which can work their way into becoming biologically available nitrogen (could be the process that started this before bacteria started to shift nitrogen to become biologically available)
-used in fertilizers in excessive, too much gets in the water and causes eutrophication. It also ends up in the atmosphere as NOx (NO and NO2) which creates smog and precursors to acid rain etc. and creates a LOT of environmental problems
-Human impact: fertilizers and fossil fuels (burning these create high temperatures)
-industrial nitrogen fixation = done in the factory under high temperatures and high pressure (conditions of little lightning bolts) – process uses natural gas burned to make this
-Haber-Bosch process -most important invention of the 20th century bc with this process we can feed 8 billion people; started out as a means to make ammunition in Germany during WWI
Carbon Cycle
-photosynthesis is converted to carbon; carbon is taken from the atmosphere, consumed, metabolized and respired again
-Human impact: burning and use of fossil fuels; life buried the carbon that was previously placed in the atmosphere was buried and now we’re taking it and pumping more carbon dioxide into the atmosphere
-deforestation causes increase in carbon dioxide due to the trees dying and decomposing into the soil
-carbon in the atmosphere has been increasing; causing an increase in greenhouse gases aka the thermal blanket that reflects back
Main Point of Chapter 7
-humans account for 2/3 of the phosphorus reaching the oceans
-nitrates contribute to eutrophication
-haber bosch process has doubled the amount of nitrogen
-denitrification is increasing through agriculture and deforestation and vegetation clearance
-carbon: global atmospheric balance: burning fossil fuels and deforestation
-humans have changed these cycles which is resulting in climate change issues today
-think of lithosphere, hydrosphere, biosphere and atmosphere; where each of the elements are going through, trace it through each of the spheres; be comfortable with how these elements are moving around through the different spheres
What is the haber bosch process?
a method of directly synthesizing ammonia from hydrogen and nitrogen developed by haber and bosch in the first decade of the 20th century; ammonia is a major component of fertilizers used to promote plant growth
