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

Chapter 3: Matter, Energy, and Life

Define matter, atoms, moleculesDefine energy and energy flowDefine 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 (by-products)

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


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


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


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


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


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


3. The Phosphorus Cycle Reintroduced to the environment

through decomposition of organic material


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)


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

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

Documents