1. Environmental Science DCHS Mr. Wustrack

2. Differentiate among an atom, an element, a molecule, and a compound. Discuss how various macromolecules are essential to life. Identify some unusual properties of water.

3.  Chemistry and the environment ◦ Understanding chemistry is crucial to our knowledge of how it can hurt and help the environment  CO 2 and methane gas harmful to ozone  Pesticides and other chemicals polluting water  Bacteria and fungus can be used to clean up soil contaminated with gasoline  Wheat, tobacco, water hyacinth, and cattails have been used to clean up toxic waste sites.

4.  Building Block of Chemistry ◦ All material in the universe that has mass and occupies space is called matter.  Atoms and Elements ◦ Basic units of matter are atoms ◦ Element is a chemical substance with a given set of properties that cannot be broken down into substances with other properties

5.  Atoms have 3 subatomic particles ◦ Nucleus  Protons – positive charge (+1)  Neutrons – no charge ◦ Electron – negative charge (-1)  Bonding ◦ When atoms combine by either sharing or giving/receiving electrons it is called chemical bonding  Ionic  covalent

6.  Ionic Bonding ◦ Atoms of different elements giving and receiving electrons ◦ Between metals and nonmetals  Covalent Bonding ◦ Atoms of different or the same elements share electrons ◦ Stronger than ionic bonding ◦ usually between nonmetals

7.  Molecules and Compounds ◦ Molecules – substances whose atoms are joined together by covalent bonds  O 2 ; C 6 H 12 O 6 ◦ Compounds – substances whose atoms are joined together by ionic bonds.  NaCl; H 2 O

8.  Organic vs. Inorganic Molecules ◦ Organic  Living things consist of organic molecules  Consist of carbon atoms bonded to carbon or hydrogen atoms ◦ Inorganic  Lack carbon to carbon bonds ◦ Hydrocarbons  Organic compound containing only hydrogen and carbon atoms

9.  Solutions are mixtures of elements, molecules, and compounds without bonding chemically and all ingredients are evenly distributed. ◦ Liquids ◦ Solids ◦ Gases ◦ Air????  Nitrogen, oxygen, water, carbon dioxide, methane (CH 4 ), and ozone (O 3 )

10.  Organic molecules sometimes form long chains called polymers which are essential to life on earth ◦ Lipids are not a polymer but still essential to life  4 types of macromolecules ◦ Proteins ◦ Nucleic Acids ◦ Carbohydrates ◦ Lipids

11.  Proteins ◦ Proteins come in many forms  Production of bones, skin, hair, muscles, and other body tissues  Others store energy  Transport substances  Immune system  Hormones  Serve as chemical messengers through an organism  Enzymes  Promote chemical reactions within cells and the body

12.  Nucleic Acids ◦ Direct protein production ◦ DNA and RNA  Composed of long chains of nucleotides  Nucleotide contains one sugar group, 1 phosphate group, and 1 nitrogenous base  DNA used by make messenger RNA in the nucleus of the cell  mRNA used by the ribosome to make protein chains in the cytoplasm of the cell ◦ DNA is inherited from an organisms “parents”  From gametes (sex cells)  sperm and egg

13.  Carbohydrates ◦ Polymers containing carbon, hydrogen, and oxygen  Usually in some multiple of CH 2 O  Glucose (C 6 H 12 O 6 ) ◦ Important for insects and crustaceans in forming chitin for their hard outer shell. ◦ Complex carbohydrate called cellulose which forms the cell walls of plant cells

14.  Lipids ◦ Do not dissolve in water ◦ Fats, oils, waxes, phospholipids and steroids are types of lipids  Fats – stores energy  Phospholipids – primary component of cell membranes  Waxes – bees honeycombs  Steroid hormones – produces body changes  Testosterone, estrogen, and androgen

15.  Covers 70% of earth’s surface  Evidence demonstrates life originated in water and stayed there for 3 billion years before moving to land  All living things rely on water for survival  A polar molecule ◦ Has a partial negative charge at the oxygen end and positive charge at the hydrogen end; due to this charge water sticks to itself by hydrogen bonds ◦ Hydrogen bonds are loose connections which give water several unique properties

16.  Cohesion ◦ Water sticking to itself  Allows transport of materials in plants and animal cells  Cohesion is so strong that some animals can literally walk on water

17.  Resistance to temperature change ◦ Water can absorb energy with only a small amount of change in temperature  Coasts are cooler in warm weather and warmer in cold weather  Ice Density ◦ Water molecules are further apart as ice than as water so ice is less dense than water.  This is opposite of most other compounds which becomes denser as it freezes.  Universal Solvent ◦ Dissolves many other molecules in solution

18.  Water breaks down into 2 ions ◦ Hydrogen ion H + ◦ Hydroxide ions OH - ◦ Water has equal number of these ions so it is considered neutral pH  Acidic ◦ Higher concentration of H + ◦ The higher the concentration the more acidic the solution  Basic ◦ Higher concentration of OH - ◦ Higher the concentration the more basic or alkaline a solution

19.  The acidity or alkalinity of a solution is described as pH ◦ Scale runs from 0-14 ◦ 7 is perfectly neutral ◦ Greater than 7 is basic  The lower it is, the stronger the acid ◦ Less than 7 is acidic  The higher it is, the stronger the base

20.  Describe two major ways the Earth’s systems interact.  Define Earth’s geosphere, lithosphere, biosphere, atmosphere, and hydrosphere.

21.  System ◦ A network of relationships among parts, elements, or components that interact with and influence one another through the exchange of energy, matter, or information.  Earth’s environment ◦ A complex interlinking system of living and nonliving components  Cycles in nature  Elements, compounds, nutrients, energy, etc.

22.  Interacting systems ◦ May exchange energy, matter, and information with other systems.  Earth’s systems ◦ Inputs  Energy  Geothermal  Solar  Life processes of organisms  Fossil fuel combustion  Information  Sensory cues  Genetics (genes)

23.  Earth’s Systems Con’t ◦ Input  Matter  Chemical input (photosynthesis; cellular respiration) ◦ Input vs. output  Photosynthesis  Input of carbon dioxide, water, sunlight  Output of oxygen, glucose  Gulf of Mexico  Output of shrimp or fish  Input to the digestive system

24.  Feedback loop ◦ When an event is both a cause, or input, and an effect, or output, in the same system.  Can be either negative or positive ◦ Negative  The system is moving in one direction acts as input that causes the system to move in the other direction.  Body cools……then too cold……brain tells body to shiver…..warms body….  Gets too warm???

25.  Positive ◦ Drives system in the same direction…to the extreme  Erosion is an example of positive feedback ◦ Can alter a system dramatically  Not many in nature  Common when system is changed by humans

26.  Earth’s “Spheres” ◦ Geosphere  All the rock at and below the earth’s surface ◦ Lithosphere  Hard rock on and just below the earth’s surface  the outermost layer of the geosphere ◦ Biosphere  All the living or once-living things and the nonliving parts of the environment with which they interact. ◦ Atmosphere  Layers of gases surrounding our planet ◦ Hydrosphere  Encompasses all water  Salt, fresh; liquid, ice, and vapor on the surface, underground, and in the atmosphere.

27. They are interconnected and overlap

28.  Describe the parts of Earth’s geosphere.  Describe Earth’s biosphere and atmosphere.  Discuss the water cycle

29.  Crust, mantle and core ◦ Crust  Thin layer of relatively cool rock that forms outer skin of the earth’s surface  Both dry land and the ocean floor. ◦ Mantle  Layer of very hot but mostly solid rock  Upper layer of mantle and crust make up the lithosphere.

30.  Core ◦ Outer and inner core  Outer – molten metals such as iron and nickel that are almost as hot as the surface of the sun.  Inner – dense ball of solid metal ◦ The heat from the outer core pushes the asthenosphere's soft rock upward (as it warms). The rock then sinks downward as it cools, like a gigantic conveyor belt  This process is called convection.

31.  Plate Tectonics ◦ As asthenosphere moves it drags along large plates of the lithosphere called tectonic plates. ◦ About 15 major plates ◦ Move about 2-15 cm per year ◦ Influences climate which effects life’s evolution  Affects rates of soil formation, erosion, and deposition ◦ Collisions and separations have resulted in landforms  Mountains  Trenches  Islands

32.  Pangaea ◦ Continents have combined, separated, and recombined  Scientists have discovered through rock formations that the continents have done this at least twice.  Most recent is called Pangaea

33.  Plate Boundaries ◦ Divergent  Plates moving apart due to magma (molten rock) surging upward creating new crust as it cools.  Mid Atlantic Ridge ◦ Convergent  Subduction  One plate slide beneath another  Crust that dives is heated and can cause magma to erupt through surface of volcanoes  Mountain Building  Plates collide together pushing each upward forming mountains

35.  Transform boundary ◦ Two plates are side by side and slide against each other  Usually results in earthquakes  San Andreas Fault

36.  Biosphere ◦ Part of the earth in which living interact with nonliving things.  Think of it as the “living earth”  Atmosphere ◦ Layer of gases such as oxygen and ozone that support life on the earth  Ozone  Protects earth from sun’s radiation  Carbon Dioxide and methane  Green house gases that keep the earth warm  “Greenhouse Effect”

37.  All of the water above and below the earth’s surface ◦ 97.5% salt water ◦ 2.5% freshwater  1.8% is ice  Known as the cryosphere  That leaves.7% for drinking or watering crops ◦ Most of that water needs to be pumped or wells drilled to be brought to the earth’s surface for our use.  Limited availability at time

38.  Summary of how water flows and changes from various states (liquid, solid, gas) ◦ Evaporation  From liquid to gas  Moves water from bodies of water and groundwater to the atmosphere ◦ Transpiration  Release of water vapor into the atmosphere by plant leaves ◦ Precipitation  Water from atmosphere to the earth’s surface  Snow, rain, sleet, hail, etc. ◦ Condensation  Change in state – from gas to a liquid

40.  Changing the states of water ◦ Solid liquid gas  Increase in energy input ◦ Gas liquid gas  Energy is removed  Ground water ◦ Fresh water found underground ◦ Aquifers – underground water storage areas  Human impact ◦ Irresponsible use of ground water ◦ Industrial gases causing acid rain  Sulfur dioxide and nitrogen oxide gases CVCV CVCV CVCV CVCV

41.  Explain how the law of conservation of matter applies to the behavior of nutrients in the environment  Describe the carbon cycle  Describe the events of the phosphorus cycle  Explain the importance of bacteria to the nitrogen cycle

42.  Consider this: ◦ A carbon atom in your fingernail today might have helped make up the muscle of a cow a year ago, may have belonged to a blade of grass a month ago before that, and may have been part of a dinosaur’s tooth 100 million years ago. Matter is never used up, and it never goes away. It just keeps cycling around and around.

43.  Why does water in the environment never actually get used up???  Law of Conservation of Matter ◦ In any system, matter is transformed from one type to another. ◦ Water – solid to liquid to gas ◦ Chemical Reaction (Balancing equations)  C 6 H 12 0 6 + O 2 = H 2 O + CO 2

44.  Nutrients ◦ Matter that organisms require for their life processes. ◦ 2 types  Macronutrients – needed in large amounts  Nitrogen, carbon, and phosphorus  Micronutrients – needed in small amounts  Magnesium, sodium  Biogeochemical cycles ◦ “nutrient cycles” ◦ Complex cycles in nature where nutrients continuously circulate throughout the environment

45.  Carbon Cycle ◦ Describes the routes that carbon atoms take through the environment  Producers ◦ Produce their own food  Use carbon dioxide and water and sunlight to produce oxygen and carbohydrates (glucose) in a process known as photosynthesis ◦ Use carbohydrates for energy  Consumers ◦ Consumers must consume other organisms to obtain their nutrients and energy

46.  Decomposers ◦ Break down wastes and dead organisms to absorb nutrients  Cellular respiration ◦ Process by which glucose and oxygen react with each other to form carbon dioxide, water, and chemical energy in the form of ATP.  A substance “sink” ◦ A reservoir of a substance that accepts more of that substance that it releases  Plants are a carbon sink  Photosynthesis and cellular respiration

47.  Human impacts on carbon cycle ◦ Shifts to atmosphere  Extracting fossil fuels releases carbon from lithosphere  Burning fossil fuels releases carbon dioxide  Cutting trees and burning of forests release carbon from plant storage and reduces plants available to use it.  Producers cannot absorb enough carbon to keep up with human activities.

49.  Phosphorus is a key component in cell membranes and life molecules such as DNA and RNA  Amount of available phosphorus is scarce ◦ Large amounts in rock and sediment but must be worn down by water and wind.  This scarcity, along with the need that organisms have for phosphorus explains why plant and algae growth often jumps dramatically when added to their environments.

50.  Human Impact ◦ Mined for fertilizer ◦ Release phosphorus rich waste water from houses and businesses  Added to detergents to help in cleaning  Can lead to overgrowth of producers in a process called eutrophication  This can lead to hypoxia which is a lack of oxygen in a body of water which causes a dead zone.

52.  Nitrogen makes up about 78% of the atmosphere by mass  Essential component in proteins, DNA, RNA, and plant growth  However, nitrogen gas cannot be cycled out of the atmosphere and into organisms ◦ Requires the right kind of chemical reaction assisted by lightening, specialized bacteria, or human technology for it to be usable by organisms ◦ Those compounds act as a potent fertilizer in the biosphere

53.  Nitrogen fixation ◦ Nitrogen gas (N 2 ) converted chemically into ammonia (NH 3 ) ◦ The intense energy from a lightening strike ◦ Air in the top layer of the soil come in contact with particular types of nitrogen-fixing bacteria

54.  Nitrification and Denitrification ◦ Other types of bacteria use ammonium ions (NH 4 + ) from nitrogen fixation or from wastes of decomposers to perform nitrification  Ammonium converted to nitrite ions (NO 2 - ) and then into nitrate ions (NO 3 -2 ).  Plants can take up nitrate ◦ Nitrogen cycle is complete when denitrification by bacteria (yet another type) converts nitrates in soil or water back into nitrogen gas