1. Chapter 3: Matter, Energy, and Life
Define matter, atoms, molecules
Define energy and energy flow
Define basic fundamentals of Ecology

2. I. From Atoms to Cells A. General Information
1. Ecology – The study of the relationships between organisms and their environment
Studies the life histories, distributions, and behaviors of individual species
Studies the structure and function of naturals systems at the level of populations, communities, ecosystems, and landscapes

3. I. From Atoms to Cells A. General information
2. Holistic approach to ecology
Uses systems to study interactions
Observe the interconnected nature of systems and organisms within
B. Atoms, Molecules, and Compounds
1. Matter – everything that has mass and takes up space
It exists in 3 distinct states
Solid, liquid, and gas

4. I. From Atoms to Cells B. Atoms, Molecules, and Compounds
Atoms have unique chemical forms called Elements
Cannot be broken down into simpler forms by ordinary chemical reactions
4 elements make up 96% of the mass of all organisms
The elements are O, C, H, N
2. Atoms - the smallest particles that exhibit the characteristics of the element
Composed of electrons, protons, and neutrons

5. I. From Atoms to Cells
Atomic number is the number of protons and is used to form the periodic table
The number of neutrons may differ creating isotopes
Atoms can join together to form molecules
Molecules are any two atoms joined together
Compounds are molecules created with different types of atoms
Chemical bonds hold atoms together
2 major types of bonds are ionic and covalent

6. I. From Atoms to Cells 3. Ions Make up acids and bases
Unequal numbers of electrons and protons
Positive ions form acids (give up electrons readily, i.e. electron donors)
Negative ions form bases (can bond easily with hydrogen ions, i.e. electron acceptors)
The number of free hydrogen (hydronium) ions and hydroxide ions in solution is used to create the pH scale

7. I. From Atoms to Cells 4. Organic Compounds
Some elements are used, by organisms, in abundance
Some elements are used, by organisms, in trace amounts
Any compound containing carbon is called an organic compound
4 major categories of organic compounds
Carbohydrates
Sugars, instant energy

8. I. From Atoms to Cells Lipids Fats and oils Also called hydrocarbons
Long chains of carbon with 2 Hydrogen atoms attached
Proteins
Made up of amino acids
Composed of amine group and carboxyl group

9. I. From Atoms to Cells 5. Cells Fundamental units of life
Nucleic acids
Made up of deoxyribose, phosphate group and a nitrogen base
DNA
5. Cells
Fundamental units of life
Some are single-celled
Bacteria, algae, protozoa
Some are multi-celled
Plants, animals, fungi

10. I. From Atoms to Cells 5. Cells (cont.)
Chemical reactions occur because of enzymes
Otherwise cells would burn up due to the combustion of metabolism
Energy transfer is called metabolism in cells
For example, sugar to ATP

11. II. Energy and Matter 1. General Information
Essential constituents of all living organisms
Energy provides the force to hold structures, tear apart structures, and move materials
2. Energy Types and Quantities
Energy is defined as the “ability to do work”
Kinetic Energy – is the energy of movement

12. II. Energy and Matter
Potential Energy – is stored energy, the energy of position
Chemical Energy – is the energy stored in the food you eat, energy of chemical bonds
Measured as Joules (physics), BTU’s (propane), and Calories (food)
Power is the rate of doing work
Heat describes the total energy not used in the movement of an object; lost energy

13. II. Energy and Matter 3. Conservation of Matter
Temperature is the speed of motion of an atom
3. Conservation of Matter
Matter, like energy, is neither created nor destroyed
Called the Conservation of Matter
Matter is transformed and combined

14. II. Energy and Matter 4. Thermodynamics and Energy Transfers
Organisms use gases, water and nutrients
Metabolism – waste products are returned to the environment in a different form (by-products)
Energy is not recycled (in the biosphere)
Must provide energy from an external source

15. II. Energy and Matter
Energy has a one-way path that eventually ends up in a low-temperature sink
First Law of Thermodynamics
Energy is conserved
Cannot be created nor destroyed, only transferred from one form to another form
Second law of Thermodynamics
As energy is transferred or transformed, there is less energy to do work
Energy is ‘lost’ to the environment

16. II. Energy and Matter
Recognizes a tendency of all natural systems to go from a state of order toward a state of increasing disorder
Entropy – “Entropy Rules!”
Also called the ‘Chaos Theory’
For example: Life to Death

17. III. Energy for Life 1. Solar Energy: Warmth and Light
Organisms survive at different temperature ranges
Low temps affect metabolism negatively, not enough energy produced to survive
High temps break down molecules rendering them non-functional
Photosynthesis converts sunlight into organic compounds that can be used as energy

18. III. Energy for Life 1. Solar Energy: Warmth and Light
Cellular respiration converts the organic compounds of photosynthesis into ATP

19. IV. From Species to Ecosystems
1. Populations, Communities and Ecosystems
Species are all of the organisms that are genetically similar enough to reproduce viable offspring
Populations consist of all of the members of a species living in a given area at a given time
Extinctions can be large scale (complete) and small scale (local)

20. IV. From Species to Ecosystems
1. Populations, Communities and Ecosystems
A community is all of the populations of organisms living and interacting in a particular area
An ecosystem is the biological community and its physical environment
Boundaries between communities and ecosystems may be difficult, but must occur
Ecosystems are separated based on communities, climate, and productivity of the communities

21. IV. From Species to Ecosystems
2. Food Chains, Webs, and Trophic Levels
Primary Productivity is the amount of biomass produced in a given area
Higher productivity ecosystems – TRF, TSF, and Wetlands
Lower productivity ecosystems – Deserts, Tundra
Net Primary Productivity includes decomposition and can change the scale of productivity
TRF is no longer a high productivity ecosystem

22. IV. From Species to Ecosystems
2. Food Chains, Webs, and Trophic Levels
Consumption of plants is considered Secondary productivity
Food Chains are a linking of feeding series between organisms
For example, Grass  Grasshopper  Frog
Or Grass  Cow  Man (steak, yeah baby!)
In communities, consumers have primary food sources
Will eat that food source first
Some consumers have secondary food sources
Don’t compete as well for this food source

23. Food Chain

24. Food Web

25. IV. From Species to Ecosystems
2. Food Chains, Webs, and Trophic Levels
Some consumers are opportunistic
Stumble on food (not the norm)
Will eat primary food source, but will anything it happens across
Typically are called omnivore
Examples are bears, raccoons
A Trophic Level is an organisms ‘feeding’ status
Producers are the first trophic level (autotroph)

26. IV. From Species to Ecosystems
Primary consumers are the second trophic level (herbivore)
Secondary consumers are the third trophic level (carnivore)
There is energy ‘loss’ at each trophic level
Typically the consumer receives 1/10th of the energy… 9/10th is lost
Most food chains are 3 trophic levels, some are 4, very few are 5
Due to the energy loss during each consumption

28. IV. From Species to Ecosystems
Tertiary consumers are either top carnivores or scavengers (third, fourth, or fifth trophic level)
Detritovores consume leaf litter, debris, and dung (third, fourth, or fifth trophic level)
Decomposers finish the break-down process of materials (third, fourth, or fifth trophic level)
Turns the material into very elemental forms

30. IV. From Species to Ecosystems
3. Ecological Pyramids
Number of organisms (by percent) in each trophic level
Can be used to describe the available energy for habitats, communities, or ecosystems

32. V. Material Cycles and Life Processes
1. The Carbon Cycle
Has 2 purposes for organisms
Structural component of organic molecules
Energy storage in the chemical bonds
Starts with CO2 intake by producers
Carbon is incorporated into sugar
Sugar is burned in all organisms through Cellular Respiration, releasing CO2 into the ecosystem

33. V. Material Cycles and Life Processes
1. The Carbon Cycle (cont.)
Some carbon is lost to ‘carbon sinks’
Ex. Coal, Oil, and Trees
Carbon is not released until combustion
Calcium Carbonate (CaCO3) is incorporated into shells of organisms
Very difficult to break down, especially in anoxic conditions at the bottom of lakes and oceans

35. V. Material Cycles and Life Processes
2. The Nitrogen Cycle
Organisms can not exist without organic compounds comprised of Nitrogen
Ex. Proteins, nucleic acids, amino acids, etc.
Inorganic forms of Nitrogen are utilized by plants to form organic compounds
Nitrogen is the most abundant element in the atmosphere, but it is unusable as N2

36. V. Material Cycles and Life Processes
2. The Nitrogen Cycle (cont.)
The nitrogen cycle provides usable N for plants
Nitrogen-fixing bacteria turn the N2 into usable N for plants (NH3 : ammonia)
Nitrite forming bacteria change NH3 into NO2 (nitrite)
Nitrate forming bacteria converts NO2 into NO3 (nitrate)
NO3 is used by the plants

37. V. Material Cycles and Life Processes
2. The Nitrogen Cycle (cont.)
Plants convert NO3 into NH4 (ammonium)
NH4 is used to create amino acids
Nitrogen re-enters the system when organisms die through decomposition
Nitrogen, also, re-enters the system through metabolic waste (uric acid)
Urination dumps nitrogen (called pulses) into streams, rivers, and soil
Bacteria consume and turn the waste into NH3

39. Root Nodules containing N-fixing bacteria

40. N-fixing bacteria

41. V. Material Cycles and Life Processes
3. The Phosphorus Cycle
Phosphorus is used by organisms for energy transfer processes
Major component of fertilizers
Begins with phosphorus leaching from rocks into groundwater
Inorganic phosphorus is absorbed by producers
Turned into organic compounds

42. V. Material Cycles and Life Processes
3. The Phosphorus Cycle
Reintroduced to the environment through decomposition of organic material

44. V. Material Cycles and Life Processes
4. The Sulfur (Sulphur) Cycle
Used in proteins
Determine acidity of rainfall, surface water, and soil
Most is in the form of rocks and minerals
Iron disulfide (FeS2), calcium sulfate (CaSO4)
Inorganic sulfur is released into the atmosphere as SO2 and SO4 (Sulfate)

45. V. Material Cycles and Life Processes
4. The Sulfur (Sulphur) Cycle (cont.)
Sulfur has many oxidative states
Ex. Hydrogen Sulfide (H2S), Sulfur Dioxide (SO2), Sulfate ion (SO4-), and S (elemental)
Human activities release sulfur
Ex. Burning of fossil fuels
Phytoplankton release large quantities of sulfur to the atmosphere (especially during warming trends)
DMS  SO2  SO4 (DMS is Dimethylsulfide)
Increases the earth’s albedo