Transcript Chapter 3: Matter, Energy, and Life

Chapter 3: Matter, Energy,
and Life
Define matter, atoms, molecules
Define energy and energy flow
Define basic fundamentals of Ecology
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
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
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
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
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
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
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
I. From Atoms to Cells
 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
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
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
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
II. Energy and 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
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 (byproducts)
 Energy is not recycled (in the biosphere)
 Must provide energy from an external
source
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
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
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
III. Energy for Life
 1. Solar Energy: Warmth and Light
 Cellular respiration converts the organic
compounds of photosynthesis into ATP
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)
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
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
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
Food Chain
Food Web
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)
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
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
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
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
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
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
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
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
Root Nodules containing N-fixing
bacteria
N-fixing bacteria
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
V. Material Cycles and Life
Processes
 3. The Phosphorus Cycle
 Reintroduced to the environment
through decomposition of organic
material
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)
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