EcologyThe branch of biology that
deals with the interactions between organisms and the
relationship between organisms and the
environment.
Do Now: Draw a flow chart to represent the
organizational relationships between the following terms from the most inclusive to the least inclusive: ecosystem, population, species, community, and biosphere.
Levels of Organization Cellular
Organization– Cells– Tissues– Organs– Organ Systems– Organisms– SPECIES
Ecosystem Organization– Species– Population– Community– Ecosystem– Landscape– Biosphere
SpeciesA group of organisms capable of
producing more members of the same organism..
Homo sapiens with Homo sapiens
Not Homo sapiens with Homo habilus
Community Includes all the populations
in a given area.
Ex: all plants, animals, and microorganisms make up a
pond community
EcosystemIncludes all the members of the
community plus the physical environment in which they live
in.–Interaction of biotic and abiotic
factors
Abiotic Factors Nonliving factors. The abiotic factors of an ecosystem include the
physical and chemical factors that affect the capacity of an organism to live and reproduce. These factors are:
1. Intensity and duration of light
2. Temperature range
3. Amount of moisture
4. Type of substrate
5. Availability of inorganic substances and gases
6. pH
Biotic Factors Living factors These factors directly or indirectly
affect the environment. Thus, the organisms, their presence,
parts, interaction, and wastes all act as biotic factors.
These interactions include: 1. Nutritional relationships 2. Symbiotic relationships
Requirements for a Stable Ecosystem The ecosystem involves interactions
between living and nonliving things. Certain requirements must be met for a stable ecosystem to exist:
1. There must be a constant supply of energy (sunlight for photosynthesis).
2. There must be living organisms that can incorporate the energy into organic compounds (food).
3. There must be a recycling of materials between organisms and the environment.
Limiting Factors Determines the types of organisms which
may exist in that environment. Examples are:
1. A low temperature common to northern latitudes determines in part what species of plants can exist in that area.
2. The amount of oxygen dissolved in a body of water will help determine which species of fish will exist there.
Landscape A spatially heterogeneous region that
includes several interacting ecosystems
Connections among ecosystems found in a particular area.
BiosphereThe portion of the earth in
which life exists.The biosphere is composed
of many complex ecosystems that include
water, soil, and air.
Do Now: Compare and contrast potential energy
and kinetic energy using biological or ecological examples and references
Types of energy Energy: the capacity
or ability to do work.
Potential Energy: Stored energy.
Kinetic Energy: The energy of motion.
Do Now: Define energy and briefly describe
how the different forms contribute to the continual energy needs of organisms
Heat Energy: thermal energy that flows from an object with a high temp. (heat source) to an object with a lower temp. (heat sink).
Types of energy
Thermodynamics: The study of energy & its transformations.
1st Law of Thermodynamics: energy cannot be created nor destroyed, but it can be transformed.
2nd Law of Thermodynamics: when energy is converted some usable energy is degraded into a less usable form. (Entropy)
Do Now: Cellular respiration occurs in both plant
and animal cells while photosynthesis only occur in plant cells. How are plant and animals connected via these two processes? Be sure to include balanced chemical equations as part of your answer.
Closed and Open Systems
Earth is an open system because it receives Earth is an open system because it receives energy from the sun.energy from the sun.
Types of Energy
Potential EnergyPotential Energy Mechanical (Kinetic) EnergyMechanical (Kinetic) Energy
HeatHeat Energy Energy NuclearNuclear Energy Energy
ElectricalElectrical Energy Energy
ChemicalChemical Energy Energy
Radiant (Solar)Radiant (Solar)
Energy Flow Relationships
For an ecosystem to be self-sustaining, there must be a flow of energy between organisms.
The pathway of energy flow through the living components of an ecosystem are represented by food chains and food webs.
Nutritional Relationships
Involves the transfer of nutrients from one organism to another within an ecosystem.
In terms of nutrition, organisms are either autotrophs or heterotrophs
SEE OWL LAB
Energy Losses The mouse receives energy from the food it eats.
Cells extract the food's energy for growth, acquiring food,
escaping enemies lost as heat. Some lost in the mouse's waste
(feces).
The remaining energy is stored in the mouse's body and is
available to the organism that preys on it.
About 90% of the energy is used or lost, only 10% is available to
predators.
Biological Magnification A nondegradable or slowly degradable
substance That becomes more and more concentrated
in the tissues of organisms at higher trophic levels of a food web.– * Dichloro-Diphenyl-Trichloroethane (DDT)– * Polychlorinated biphenyls (PCBs)
PCBs in Food Webs PCB concentrations in animal tissue
can be magnified up to 25 million times. Microscopic organisms pick up
chemicals from sediments Consumed in large numbers by filter
feeding zooplankton. Mysid shrimp then consume
zooplankton fish eat the mysid and so on up the food web to the
herring gull. (Figure and caption from Our Stolen
Future, p. 27)
DDT Detection In 1962, Rachel Carson,
a former U.S. Fish and Wildlife Service (USFWS) scientist and writer, published Silent Spring, outlining the dangers of DDT
Fig. 41-8, p.736
Do Now: Discuss the contributions of
saprotrophs and detritivores to a balanced ecosystem.
Identify two representatives of each group in your discussion
(A) Food Chains Green plants and other
photosynthetic organisms are the organisms in an ecosystem that can convert radiant energy from sunlight into food.
A food chain involves the transfer of energy from green plants through a series of organisms with repeated stages of eating and being eaten.
(B) Food Webs In a natural community, most organisms eat
more than one species and may be eaten, in turn, by more than one species.
Thus, the various food chains in a community are interconnected forming a food web.
SEE OWL LAB
Do Now: Define and discuss three applications of
the term: ecological pyramid. What accounts for the shape of the
pyramid? Use sketches of each type of pyramid
with associated quantitative units to support your comparison.
(C) Pyramid of Energy The greatest amount of
energy in a community is present in the organisms that make up the producer level.
Only a small portion of this energy (10%) is passed on to primary consumers, and only a smaller portion (10% of the original 10%) is passed on to secondary consumers.
A pyramid of energy can be used to illustrate the loss of usable energy at each feeding level.
B. ALL living organisms must carry
out ALL 8 life functions
Nutrition
Transport
Respiration
Excretion
Synthesis
Growth
Regulation
Reproduction
Chemosynthesis A type of autotrophic nutrition Does not require light as an energy
source Energy is obtained by chemical
reactions within the cell Example: Hydrothermal vent bacteria
PhotosynthesisThe most common type of
autotrophic nutrition In this process, organisms
use energy from sunlight, carbon dioxide, and water to make food (usually glucose)
Chloroplast
Contains pigments called: – chlorophylls (a & b greens) – Xanthophylls (yellow) – Carotenes (orange)
It is in the chloroplast that light energy is trapped by chlorophylls and glucose is formed as the product. (food)
http://seawifs.gsfc.nasa.gov/SEAWIFS.html
Which Wavelengths are the best for photosynthetic plants?
Which Wavelength is the worst?
Absorption of Light byAbsorption of Light byChlorophyll Chlorophyll aa and Chlorophyll and Chlorophyll bb
V B G YO R
Chlorophyll b
Chlorophyll a
Wavelengths effects on Photosynthesis
ROY G BIV The maximum amount of The maximum amount of
photosynthesis will occur when photosynthesis will occur when exposed to exposed to redred and and blueblue light because light because it is these two colors that are easily it is these two colors that are easily absorbed in great quantity by the absorbed in great quantity by the chlorophyll chlorophyll
For green leaves, For green leaves, greengreen light is light is reflected and therefore has the least reflected and therefore has the least affect on photosynthesisaffect on photosynthesis
Formula for Photosynthesis
6CO6CO22 + 12H + 12H22O + radiant energy O + radiant energy C C66HH1212OO66 + 6H + 6H22O + 6OO + 6O22
CC66HH1212OO66 + 6O + 6O22 + 6H + 6H22O O 6CO 6CO22 + 12H + 12H22O + work energy O + work energy
Formula for Cellular RespirationFormula for Cellular Respiration
Chloroplast
water
O2
Sugars
CO2
Light-Dependent Reactions
CalvinCycle
NADPH
ATP
ADP + PNADP+
Sunlight
Section 8-3
6CO6CO22 + 12H + 12H22O + radiant energy O + radiant energy C C66HH1212OO66 + 6H + 6H22O + 6OO + 6O22
Photosynthesis: An Overview
1. Light Reaction1. Occurs in the grana of the chloroplast.2. First stage of photosynthesis.3. Begins with the absorption of light energy
by chlorophyll.4. Photolysis occurs- a reaction in which H2O
molecules split into oxygen and hydrogen.5. All oxygen given off during photosynthesis
comes from the photolysis of water.6. ATP (Adenosine triphosphate), which is a
form of chemical energy, is produced.
Chloroplast
(H2O) (H2O)
Oxygen Oxygen (6O(6O22))
I am out of here!
Light ReactionLight Reaction
12 WATE12 WATER R moleculesmolecules
12 Hydrogen
(This all occursIn the Grana.)
12 Hydrogen
NADPHNADPH+ ATP+ ATP
AKA AKA PhotolysisPhotolysis
Dark Reaction“Calvin Cycle”“Light IndependentReaction”
12 Hydrogen12 Hydrogen
6(CO2)
NADPHNADPH+ATP+ATP
C6H1206 6(H20)
AKA Glucose
(This all occurs in the Stroma.)
Carbon Fixation
2. Dark Reaction Occurs in the stroma of the chloroplast. The second stage of photosynthesis. It is here that CO2 is converted to carbohydrates
by a process called carbon fixation.
CO2 PGAL C6H12O6 Light is not required. The dark reaction requires ATP from the light
reaction for it to take place.
Factors Affecting the Rate of Photosynthesis
1. Light Intensity
2. Water
3. Carbon dioxide level
4. Temperature
Adaptations for Photosynthesis
A. Unicellular Organisms 1. Almost all chlorophyll-containing
unicellular organisms are aquatic. (live in water)
2. The raw materials for photosynthesis are absorbed directly from the water and into the cell
Ex: algae &cyanobacteria
Adaptations for Photosynthesis
B. Terrestrial Plants (land-dwelling)
1. Occurs in leaves that provide the maximum surface area for the absorption of light.
Plants Leaves- have stomates for gas
exchange
Stems- have lenticels for gas exchange
– Roots- gas exchange occurs across a moist membrane
of root hairs (diffusion)
Do Now: Briefly explain the process of cellular
respiration and uses of the energy obtained from the process. Your answer should include the following terms: glucose, water, carbon dioxide, chemical energy, and oxygen. What organisms carry on this process?
Glucose
(C6H12O6)
2 pyruvic acid
2 ATP
2 PGAL
(C3H5O3)
Glycolysis (splitting glucose)
+4 ATP
Net Gain:???
Glycolysis (splitting glucose) Net Energy Yield from Glycolysis
Energy requiring steps:– 2 ATP invested
Energy releasing steps:– 2 NADH formed – 4 ATP formed
Net yield is 2 ATP and 2 NADH
Glycolysis (splitting glucose)All three reactions with Glycolysis Glycolysis occurs in cytoplasm Reactions are catalyzed by enzymes
Glucose 2 Pyruvate
(six carbons) (three carbons)
Aerobic RespirationAerobic Respiration
Glucose + OGlucose + O22 H H22O + COO + CO22 + 36 ATP’s + 36 ATP’s Again, enzymes are used and a net of 36 Again, enzymes are used and a net of 36
ATP’s are producedATP’s are produced
Equations for Anaerobic RespirationEquations for Anaerobic Respiration1. Lactic Acid Fermentation1. Lactic Acid Fermentation
glucose glucose 2 lactic acids + 2 ATP’s 2 lactic acids + 2 ATP’s
2. Alcoholic Fermentation2. Alcoholic Fermentation
glucose glucose 2 alcohol + 2 CO 2 alcohol + 2 CO22 + 2 + 2 ATP’sATP’s
In each equation, enzymes are used and a net In each equation, enzymes are used and a net gain of 2 ATP’s are producedgain of 2 ATP’s are produced
Equations for Anaerobic
Respiration
glucose 2 lactic acids + 2 ATP’s
glucose 2 alcohol + 2 CO2 + 2 ATP’s
In each equation, enzymes are used and a net gain of 2 ATP’s are produced
Equation for Aerobic
Respiration
glucose + O2 H2O + CO2 + 36 ATP’s
•Again, enzymes are used and a net of 36 ATP’s are produced
Do Now: What is the human impact on net
primary productivity? What are the potential environmental problems associated with this impact and what changes would be required to minimize human impact?
Net Primary Productivity (NPP)
=Gross Primary
Productivity (GPP) (total energy from
photosynthesis /unit area/time)
- Plant respiration (energy invested by
plants)
(NPP) = GPP (rate) – Plant Respiration
Humans Humans competecompete with other species with other species for for energyenergy. .
Our planet cannot handleOur planet cannot handlethe burden from human the burden from human overpopulationoverpopulation..
Total energy producedTotal energy producedEnergy costEnergy cost
Humans Humans competecompete with other species with other species for for energyenergy. Our planet cannot handle. Our planet cannot handlehuman human overpopulationoverpopulation..
Table 9l-1: Average annual Net Primary Productivity of the Earth's major biomes.
Ecosystem Type Net Primary Productivity(kilocalories/meter 2 /year)
Tropical Rain Forest 9000
Estuary 9000
Swamps and Marshes 9000
Savanna 3000
Deciduous Temperate Forest 6000
Boreal Forest 3500
Temperate Grassland 2000
Polar Tundra 600
Desert < 200
http://www.physicalgeography.net/fundamentals/9l.html
There are 3 basic organisms in a food web:
1)Producers
2)Consumers 2a) Primary consumers
2b)Secondary consumers
3)Decomposers
There are 3 basic organisms in a food web:
1. Producers- include green plants and other photosynthetic organisms that synthesize the organic nutrients that supply energy to other members in the community.
Question Briefly discuss the role of autotrophs in
an ecosystem
http://www.dnr.state.wi.us/org/water/fhp/lakes/under/oxygen.htm
There are 3 basic organisms in a food web:
1. Consumers- include all heterotrophic organisms. Organisms that feed on green plants are primary consumers, or herbivores. Secondary consumers, or carnivores, feed on other consumers. Omnivores eat producers and consumers.
There are three basic classes of organisms in a food web:
Decomposers – are the organisms (saprotrophs) that break down wastes and dead organisms so that chemical materials are returned to the environment for use by other living organisms.
Do Now: What are krill? Using appropriate
terminology, discuss the role of krill in the Antarctic food web, and describe what has been happening to the population of these animals over that past 150 years and why. What has been the impact on this Antarctic ecosystem of human related change in the global environment?
Do Now: Today, commercial fishermen are
“fishing down the food web.” This is unsustainable. WHY? How can this movement down the marine food web be reversed?