1. Chapter 2 & 8.1 Principles of Ecology & How Organisms Obtain Energy
Biology R/Biology
Biology Academic
Mrs. Fournier, Lance, McGraw, Reissfelder

2. 2.1 Organisms and Their Relationships
Main idea – The interactions of biotic and abiotic factors in a community or ecosystem form a tight web
Objectives
Describe the difference between abiotic and biotic factors
Describe the levels of biological organisms
Differentiate between an organism’s habitat and it’s niche
Review Vocabulary
Species: group of organisms that can interbreed and produce fertile offspring in nature

3. Ecology
The scientific discipline in which the relationships among living organisms and the interactions the organisms have with their environment are studied
In 1866, Ernst Haeckel, German biologist, first introduced the study of ecology
Ecologists are scientists who study ecology, they observe, experiment and model using a variety of tools and methods

4. The Biosphere The proportion of Earth that supports life
It extends several kilometers above the Earth’s surface into the atmosphere
It extends several kilometers below the ocean’s surface.
It includes areas such as the frozen polar regions, deserts, oceans, and rain forests

5. Biotic factors The living factors in an organism’s environment Example
All living organisms in the environment
All living organisms near the environment
All migratory organisms
The interactions among organisms are necessary for the health of all species in the same geographic location

6. Abiotic factors The nonliving factors in an organism’s environment
Examples
Temperature range - Air or water currents
Sunlight - Soil type
Rainfall - Nutrients available
pH - Salt Concentration
Organisms adapt to survive in the abiotic factors present in their natural environment.

7. Levels of Organization
The levels increase in complexity as the numbers and interactions between organisms increase.
Organism
Population
Biological Community
Ecosystem
Biome
Biosphere

8. Organism, Population and Biological Communities
The lowest level of organization is the individual organism
Individual organisms of a single species that share the same geographic location at the same time make up a population
A biological community is a group of interacting populations that occupy the same time.

9. Ecosystems, Biomes and the Biosphere
An Ecosystem is a biological community and all of the abiotic factors that affect it. Boundaries of an ecosystem are flexible and can change, and ecosystems might even overlap
A Biome is a large group of ecosystems that share the same climate and have similar types of communities
All the biomes on Earth combine to form the highest level of organization - the biosphere

10. Ecosystems Interactions
Interactions between organisms are important in an ecosystem.
A community of organisms increases the chances for survival of any one species by using the available resources in different ways
A habitat is an area where an organism lives
A niche is the role or position that an organism has in its environment
how it meets its needs for food, shelter and reproduction
requirements for living space, temperature, moisture, or in terms of appropriate mating or reproduction conditions

11. Community Interactions
Interactions include competition for basic needs such as food, shelter, and mates, as well as relationships in which organisms depend on each other for survival
Competition occurs when more than one organism uses a resource at the same time
Predation is the act of one organism consuming another organism for food
The organism that pursues another organism is the predator
The organism that is pursued is the prey

12. Symbiotic Relationships
Some species survive due to the relationships they have developed with other species
Symbiosis is the close relationship that exists when two or more species live together
Mutualism
Commensalism
Parasitism

13. Mutualism
The relationship between two or more organisms that live closely together and benefit from one another
Lichens on trees is an example of a mutualistic relationship between fungi and algae
The close association of these two organisms provides two basic needs for the organisms – food and shelter

14. Commensalism
Is a relationship in which one organism benefits and the other is neither helped or harmed.
Examples
Lichens and trees
Clownfishes and sea anemones

15. Parasitism
A symbiotic relationship in which one organism benefits at the expense of another organism
Examples
External – ticks or fleas
Internal – bacteria, tapeworms and roundworms

16. 2.2 Flow of Energy in an Ecosystem
Main idea – Autotrophs capture energy, making it available for all members of a food web
Objectives
Describe the flow of energy through an ecosystem
Identify the ultimate energy source for photosynthetic producers
Describe food chains, food webs, and pyramid models
Review Vocabulary
Energy: the ability to cause change; energy cannot be created or destroyed, only transformed

17. Energy in an Ecosystem
One way to study the interactions of organisms within an ecosystem is to follow the energy that flows through an ecosystem
Organisms differ in how they obtain energy, they are classified as autotrophs or heterotrophs based on how they obtain their energy in an ecosystem

18. Autotrophs
Is an organism that collects energy from sunlight or inorganic substances to produce food
Green plants and other organisms that produce their own food are called primary producers
They are the foundation of all ecosystems because they make energy available for all other organisms in an ecosystem

19. Heterotrophs
Is an organism that gets its energy requirements by consuming other organisms
Heterotrophs are also called consumers
Herbivore
Carnivores
Omnivores
Detrivores
Decomposers

20. Heterotrophs If it eats only plants it is a herbivore
Cow, rabbit or grasshopper
If it preys on other heterotrophs it is a carnivore
Wolves, lions, and lynxes
If it eats both plants and animals it is a omnivores
Bears, humans and mockingbirds
Detrivores eat fragments of dead matter, return nutrients to the soil, air, and water where the nutrients can be reused by organisms
Worms and many aquatic insects
Decomposers break down dead organisms by releasing digestive enzymes
Fungi and bacteria

21. Models of Energy Flow
Ecologists use food chains and food webs to model the energy flow through an ecosystem
Each step in a food chain or food web is called a trophic level
Autotrophs make up the first trophic level in all ecosystems
Heterotrophs make up the remaining levels
With the exception of the first trophic level, organisms at each trophic level get their energy from the trophic level before it

22. Food Chains
A simple model that shows how energy flows through an ecosystem
Arrows represent the one-way energy flow which typically starts with autotrophs and moves to heterotrophs
Each organism uses a portion of the energy it obtains from the organism it eats for cellular processes to build new cells and tissues
The remaining energy is released into the surrounding environment and no longer is available to these organisms

23. Food Webs
This is a model that represents the many interconnected food chains and pathways in which energy flows through a group of organisms.
Feeding relationships usually are more complex than a single food chain because most organisms feed on more than one species.
Example – Birds eat a variety of seeds, fruits and insects

24. Ecological Pyramids
Below is a diagram that shows the relative amounts of energy, biomass or numbers of organisms at each trophic level in an ecosystem

25. Pyramid of Energy
Each level represents the amount of energy that is available to that trophic level.
With each step up, there is an energy loss of 90 percent; available energy decreases
This energy is used by the organisms for cellular processes and energy is released to the environment as heat

26. Pyramid of Biomass
Biomass is the total mass of living matter at each trophic level
In a pyramid of biomass, each level represents the amount of biomass consumed by the level above it
The amount of biomass decreases at each trophic level

27. Pyramid of Numbers
Each level represents the number of individual organisms consumed by the level above it; population size decreases
The relative number of organisms at each trophic level also decreases because there is less energy available to support organisms

28. 2.3 Cycling of Matter
Main idea – Essential nutrients are cycled through biogeochemical processes
Objectives
Describe how nutrients move through the biotic and abiotic parts of an ecosystem
Explain the importance of nutrients to living organisms
Compare the biogeochemical cycles of nutrients
Review Vocabulary
Cycle: a series of events that occur in a regular repeating pattern

29. Cycles in the Biosphere
Energy is transformed into usable forms to support the functions of an ecosystem
A constant supply of usable energy for the biosphere is needed, but this is not true of matter
The law of conservation of mass states that matter is not created or destroyed
Natural processes cycle matter through the biosphere

30. Matter/Nutrients Matter Nutrients
Anything that takes up space and has mass
Provides the nutrients needed for organisms to function
Nutrients
A chemical substance that an organism must obtain from its environment to sustain life and undergo life processes
The bodies of all organisms are built from water and nutrients such as carbon, nitrogen, and phosphorous

31. Biogeochemical Cycle
The cycling of nutrients in the biosphere involves both matter in living organisms and physical processes found in the environment
The exchange of matter through the biosphere is called biogeochemical cycle
These cycles involve living organisms (bio),
Geological processes (geo), and chemical processes (chemical).

32. The Water Cycle Evaporation -
Water is constantly evaporating from bodies of water
Energy from the Sun heats the liquid water, forming the gaseous form of water called water vapor
The water vapor rises and begins to cool in the atmosphere
Clouds form when the cooling water vapor condenses into droplets around dust particles in the atmosphere

33. The Water Cycle Precipitation –
Water falls from the clouds as precipitation
Precipitation transfers water from the atmosphere to Earth’s surface
Precipitation can be in the form of rain, snow, sleet or hail
Precipitation is absorbed by the soil
Percolation of water in soil is transferred into groundwater

34. The Water Cycle
Groundwater and runoff from land surfaces flow to oceans and other bodies of water and undergo the process of evaporation
Water also evaporates from other sources of moisture, such as water in the soil
Over land, approximately 90% of the water evaporates, 10% from the surface of plants through a process called transpiration

35. The Water Cycle
Because oceans cover ¾ of Earth’s surface, most of the precipitation falls directly into the ocean.
Only about 2% of all the freshwater on Earth is held in any type of reservoir, such as an ice cap, glacier, aquifer, or lake.
The remaining water on Earth circulates through the water cycle

36. The Carbon and Oxygen Cycles

37. The Carbon and Oxygen Cycles
Carbon and oxygen often make up molecules essential for life
During a process called photosynthesis, green plants and algae convert carbon dioxide and water into carbohydrates and release oxygen back into the air
These carbohydrates are used as a source of energy for all organisms in the food web
Carbon dioxide is recycled when autotrophs and heterorophs release it back into the air during cellular respiration

38. The Carbon and Oxygen Cycles
Carbon and oxygen recycle relatively quickly through living organisms
Carbon enters a long-term cycle when organic matter is buried underground and converted to peat, coal, oil, or gas deposits
The carbon might remain as fossil fuels for millions of years
Carbon is released from fossil fuels when they are burned, which adds carbon dioxide to the atmosphere

39. The Carbon and Oxygen Cycles
Carbon and oxygen can enter a long-term cycle in the form of calcium carbonate, too.
Calcium carbonate is found in the shells of plankton and animals such as coral, clams, and oysters
These organisms fall to the bottom of the ocean floor, creating vast deposits of limestone rock
Carbon and oxygen remain trapped in these deposits until erosion processes cause calcium and carbon to become part of the short-term cycle

40. The Nitrogen Cycle

41. The Nitrogen Cycle
Nitrogen is an element that organisms need in order to produce proteins
Plants and animals cannot use nitrogen directly from the atmosphere
Nitrogen gas is captured from the air by species of bacteria that live in water, the soil, or grow on roots of some plants

42. The Nitrogen Cycle
The process of capture and conversion of nitrogen into a form that is useable by plants is called nitrogen fixation
Some nitrogen also is fixed during electrical storms when the energy from lightening bolts changes nitrogen gas to nitrates.
Nitrogen also is added to soil when chemical fertilizers are applied to lawns, crops, or other areas

43. The Nitrogen Cycle
Nitrogen enters the food web when plants absorb nitrogen compounds from the soil and convert them into proteins
Consumers get nitrogen by eating plants or animals that contain nitrogen
They reuse the nitrogen and make their own proteins
Because the supply of nitrogen in a food web is dependent upon the amount of nitrogen that is fixed, nitrogen often is a factor that limits the growth of producers

44. The Nitrogen Cycle Nitrogen is returned to the soil in several ways
When an animal urinates, nitrogen returns to the water or soil and is reused by plants
When organisms die, nitrogen returns to the soil when decomposers break down the dead organisms into the nitrogen compound ammonia.
Organisms in the soil convert ammonia into nitrogen compounds that can be used by plants
In a process called dentrification, some soil bacteria convert fixed nitrogen compounds back into nitrogen gas, which returns it to the atmosphere

45. The Phosphorous Cycle

46. The Phosphorous Cycle
Phosphorus is an element that is essential for the growth and development of organisms
It is found in various compounds of cells
The phosphorous cycle, like the carbon and oxygen cycles consists of short-term and long-term cycles

47. The Phosphorus Cycle Short-term cycle Long-term cycle
Phosphorus is cycled from the soil to producers and then from producers to consumers
When organisms die or produce waste products, decomposers return the phosphorus to the soil where it can be used again
Long-term cycle
Weathering or erosion of rocks that contain phosphorus slowly adds phosphorus to the cycle
Phosphorus, in the form of phosphates, may be present only in small amounts in soil and water
Phosphorus often is a factor that limits the growth of producers

48. Section 8.1 How Organisms Obtain Energy
Main idea – All living organisms use energy to carry out all biological processes
Objectives
Summarize the two laws of thermodynamics
Compare and contrast autotrophs and heterotrophs
Describe how ATP works in a cell

49. Transformation of Energy
All cellular activities require energy; the ability to do work
Thermodynamics is the study of the flow and transformation of energy in the universe

50. Laws of Thermodynamics
The 1st Law – “Law of conservation of energy” – Energy can be converted from one form to another, but it cannot be created nor destroyed
The 2nd Law – Energy that is “lost” is generally converted to thermal energy – “entropy increases”
Entropy – measure of disorder or unusable energy, in a system.

51. Autotrophs & Heterotrophs
Autotrophs – organisms that make their own food
Chemoautotrophs – uses chemicals as a source of energy
Photoautotrophs – convert light energy from the Sun into chemical energy
Heterotrophs – organisms that need to ingest food to obtain energy

52. Metabolism
All of the chemical reactions in a cell are referred to as the cell’s metabolism
Metabolic pathway is a series of chemical reactions in which the product of one reaction is the substrate for the next reaction
Catabolic pathways – releases energy by breaking down larger molecules into smaller ones
Anabolic pathways –uses the energy released by catabolic pathways to build larger molecules from smaller molecules
The continual flow of energy within an organism is the result of the relationship of catabolic and anabolic pathways

53. Photosynthesis
Photosynthesis is the anabolic pathway in which light energy from the Sun is converted to chemical energy for use by the cell
6CO2 + 6H2O  C6H12O6 + 6O2

54. Cellular Respiration
Cellular Respiration is the catabolic pathway in which organic molecules are broken down to release energy for use by the cells
C6H12O6 + 6O2  6CO2 + 6H2O + ATP

55. Photosynthesis & Cellular Respiration Form a Cycle

56. ATP: The Unit of Cellular Energy
Adenosine Triphosphate (ATP) is the most important biological molecule that provides chemical energy
ATP is made of an adenine base, a ribose sugar, and three phosphate groups
ATP releases energy when the bond between the second and third phosphate groups is broken, forming adenosine diphosphate (ADP) and a free phosphate group
Energy is stored in the phosphate bond formed when ADP receives a phosphate group and becomes ATP

57. ATP: The Unit of Cellular Energy