2. Chapter 4
Ecosystems & Energy

3. Ecology
The branch of biology that deals with the interactions between organisms and the relationship between organisms and the environment.

4. 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.

5. Levels of Biological Organization

6. Levels of Organization
Ecosystem Organization
Species
Population
Community
Ecosystem
Landscape
Biosphere
Cellular Organization
Cells
Tissues
Organs
Organ Systems
Organisms
SPECIES

7. Homo sapiens with Homo sapiens
Species
A group of organisms capable of producing more members of the same organism..
Homo sapiens with Homo sapiens
Not Homo sapiens with Homo habilus

8. The Brown Trout Salmo trutta
Species
The Brown Trout Salmo trutta

9. Includes all the members of a species found in a given area.
Population
Includes all the members of a species found in a given area.
Ex: sunfish in a pond

10. Community Includes all the populations in a given area.
Ex: all plants, animals, and microorganisms make up a pond community

11. Interaction of biotic and abiotic factors
Ecosystem
Includes all the members of the community plus the physical environment in which they live in.
Interaction of biotic and abiotic factors

12. 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

13. 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

14. 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:
There must be a constant supply of energy (sunlight for photosynthesis).
There must be living organisms that can incorporate the energy into organic compounds (food).
There must be a recycling of materials between organisms and the environment.

15. Limiting Factors
Determines the types of organisms which may exist in that environment.
Examples are:
A low temperature common to northern latitudes determines in part what species of plants can exist in that area.
The amount of oxygen dissolved in a body of water will help determine which species of fish will exist there.

16. Landscape
A spatially heterogeneous region that includes several interacting ecosystems
Connections among ecosystems found in a particular area.

17. The portion of the earth in which life exists.
Biosphere
The portion of the earth in which life exists.
The biosphere is composed of many complex ecosystems that include water, soil, and air.

18. Ecological Organization
Population ( or )
Community ( )
Ecosystem ( )
Biosphere ( )

19. Do Now:
Compare and contrast potential energy and kinetic energy using biological or ecological examples and references

20. Types of energy Energy: the capacity or ability to do work.
Potential Energy: Stored energy.
Kinetic Energy: The energy of motion.

21. Do Now:
Define energy and briefly describe how the different forms contribute to the continual energy needs of organisms

22. Types of energy
Heat Energy: thermal energy that flows from an object with a high temp. (heat source) to an object with a lower temp. (heat sink).

23. Nuclear Energy: energy found within atomic nuclei.

24. Types of Energy
Electrical Energy: energy that flows as charged particles.

25. 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)

26. 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.

27. Closed and Open Systems
Earth is an open system because it receives energy from the sun.

28. Types of Energy Chemical Energy Potential Energy
Mechanical (Kinetic) Energy
Radiant (Solar)
Nuclear Energy
Heat Energy
Electrical Energy

29. 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.
          

30. 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

31. Energy Flow through a food Chain

32. 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.

33. Energy Flow

34. 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)

35. DDT in Food Webs

36. DDT

37. 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)

38. 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

39. Do Now:
Discuss the contributions of saprotrophs and detritivores to a balanced ecosystem.
Identify two representatives of each group in your discussion

40. (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.

41. Food Chain

42. (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

43. Food Web at the Edge of an Eastern Deciduous Forest

44. 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.

45. (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.

48. B. ALL living organisms must carry out ALL 8 life functions
Nutrition
Synthesis
Transport
Growth
Respiration
Regulation
Reproduction
Excretion

49. An organism capable of making their own food
Autotroph
An organism capable of making their own food
Photosynthetic
Chemosynthetic

50. 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

51. Photosynthesis The most common type of autotrophic nutrition
In this process, organisms use energy from sunlight, carbon dioxide, and water to make food (usually glucose)

52. 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)

53. Structure of Chloroplast

54. Wavelengths effects on Photosynthesis
Absorption of Light by
Chlorophyll a and Chlorophyll b
Which Wavelengths are the best for photosynthetic plants?
Which Wavelength is the worst?
Chlorophyll b
Chlorophyll a V B G Y O R

55. ROY G BIV
The maximum amount of photosynthesis will occur when exposed to red and blue light because it is these two colors that are easily absorbed in great quantity by the chlorophyll
For green leaves, green light is reflected and therefore has the least affect on photosynthesis

56. Formula for Photosynthesis
6CO2 + 12H2O + radiant energy  C6H12O6 + 6H2O + 6O2
Formula for Cellular Respiration
C6H12O6 + 6O2 + 6H2O  6CO2 + 12H2O + work energy

57. Photosynthesis and Cellular Respiration

58. Photosynthesis occurs in two stages:
Light Reaction
Dark Reaction

59. Structure of Chloroplast
Light reactions
Dark reactions

60. Photosynthesis: An Overview
Section 8-3
6CO2 + 12H2O + radiant energy  C6H12O6 + 6H2O + 6O2
Sunlight
water O2
Sugars
CO2
Chloroplast
NADP+
ADP + P
Light-
Dependent
Reactions
Calvin
Cycle
ATP
NADPH

61. 1. Light Reaction Occurs in the grana of the chloroplast.
First stage of photosynthesis.
Begins with the absorption of light energy by chlorophyll.
Photolysis occurs- a reaction in which H2O molecules split into oxygen and hydrogen.
All oxygen given off during photosynthesis comes from the photolysis of water.
ATP (Adenosine triphosphate), which is a form of chemical energy, is produced.

62. Light Reaction Oxygen (6O2) Chloroplast (H2O) AKA Photolysis NADPH
I am out of here!
12 WATER molecules
(H2O)
12 Hydrogen
12 Hydrogen
AKA
Photolysis
NADPH
+ ATP
(This all occurs
In the Grana.)

63. Dark Reaction (This all occurs in the Stroma.) NADPH +ATP 6(CO2)
“Calvin Cycle”
“Light
Independent
Reaction”
(This all occurs in the Stroma.)
NADPH
+ATP
12 Hydrogen
12 Hydrogen
Carbon Fixation
6(CO2)
C6H1206
6(H20)
AKA
Glucose

64. The Food Factory 4 3 1 ? ? ? 2
*6* 5

66. 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.

67. Factors Affecting the Rate of Photosynthesis
Light Intensity
Water
Carbon dioxide level
Temperature

68. 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

69. Adaptations for Photosynthesis
B. Terrestrial Plants (land-dwelling)
1. Occurs in leaves that provide the maximum surface area for the absorption of light.

70. 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)

71. 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?

72. Glycolysis (splitting glucose)
2 ATP
2 PGAL
(C3H5O3)
2 pyruvic acid
Glucose
(C6H12O6)
+4 ATP
Net Gain:???

73. 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

74. Glycolysis (splitting glucose)
All three reactions with Glycolysis
Glycolysis occurs in cytoplasm
Reactions are catalyzed by enzymes
Glucose 2 Pyruvate
(six carbons) (three carbons)

75. Equations for Anaerobic Respiration
1. Lactic Acid Fermentation
glucose  2 lactic acids + 2 ATP’s
2. Alcoholic Fermentation
glucose  2 alcohol + 2 CO2 + 2 ATP’s
In each equation, enzymes are used and a net gain of 2 ATP’s are produced
Aerobic Respiration
Glucose + O2  H2O + CO ATP’s
Again, enzymes are used and a net of 36 ATP’s are produced

76. 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

77. Equation for Aerobic Respiration
glucose + O2  H2O + CO ATP’s
Again, enzymes are used and a net of 36 ATP’s are produced

78. Who am I?

79. 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?

80. Net Primary Productivity (NPP) = Gross Primary Productivity (GPP) (total energy from photosynthesis /unit area/time) - Plant respiration (energy invested by plants)

81. (NPP) = GPP (rate) – Plant Respiration
Total energy produced
Energy cost
Humans compete with other species
for energy.
Our planet cannot handle
the burden from human overpopulation.

82. Humans compete with other species for energy. Our planet cannot handle
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
 Swamps and Marshes
 Savanna
 3000
 Deciduous Temperate Forest
 6000
 Boreal Forest
 3500
 Temperate Grassland
 2000
 Polar Tundra
 600
 Desert
 < 200
Humans compete with other species
for energy. Our planet cannot handle
human overpopulation.

83. There are 3 basic organisms in a food web:
1)Producers
2)Consumers
2a) Primary consumers
2b)Secondary consumers
3)Decomposers

85. There are 3 basic organisms in a food web:
Producers- include green plants and other photosynthetic organisms that synthesize the organic nutrients that supply energy to other members in the community.

86. Question Briefly discuss the role of autotrophs in an ecosystem

87. There are 3 basic organisms in a food web:
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.

88. 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.

89. Antarctic food web

90. Antarctic food web
Krill!

91. 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?

92. 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?

93. D-End