SCIENCE 10 A.P. STUDY GUIDE 2011 Holy Trinity Academy 1 Unit ONE: Chemistry 1. Describe the basic particles that make up the underlying structure of matter, and investigate related technologies a.identify historical examples of how humans worked with chemical substances to meet their basic needs b. outline the role of evidence in the development of the atomic model consisting of protons and neutrons (nucleons) and electrons; i.e., Dalton, Thomson, Rutherford, Bohr c. identify examples of chemistry-based careers in the community 2. Explain, using the periodic table, how elements combine to form compounds, and follow IUPAC guidelines for naming ionic compounds and simple molecular compounds a. illustrate an awareness of WHMIS guidelines, and demonstrate safe practices in the handling, storage and disposal of chemicals in the laboratory and at home b. explain the importance of and need for the IUPAC system of naming compounds, in terms of the work that scientists do and the need to communicate clearly and precisely c. explain, using the periodic table, how and why elements combine to form compounds in specific ratios d. predict formulas and write names for ionic and molecular compounds and common acids, using a periodic table, a table of ions and IUPAC rules e. classify ionic and molecular compounds, acids and bases on the basis of their properties; i.e., conductivity, pH, solubility, state f. predict whether an ionic compound is relatively soluble in water, using a solubility chart g. relate the molecular structure of simple substances to their properties h. outline the issues related to personal and societal use of potentially toxic or hazardous compounds 3. Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law of conservation of mass a. provide examples of household, commercial and industrial processes that use chemical reactions to produce useful substances and energy b. identify chemical reactions that are significant in societies c. describe the evidence for chemical changes; i.e., energy change, formation of a gas or precipitate, colour or odour change, change in temperature d. differentiate between endothermic and exothermic chemical reactions 2 e. classify and identify categories of chemical reactions; i.e., formation (synthesis), decomposition, hydrocarbon combustion, single replacement, double replacement f. translate word equations to balanced chemical equations and vice versa for chemical reactions that occur in living and nonliving systems g. predict the products of formation (synthesis) and decomposition, single and double replacement, and hydrocarbon combustion chemical reactions, when given the reactants h. define the mole as the amount of an element containing 6.02 × 1023 atoms (Avogadro’s number) and apply the concept to calculate quantities of substances made of other chemical species i. interpret balanced chemical equations in terms of moles of chemical species, and relate the mole concept to the law of conservation of mass Introduction and Review Chemistry: The study of matter, its properties, composition, and behaviors WHMIS: Workplace Hazardous Materials Information System A set of eight symbols to quickly identify the potential hazard a substance presents. MSDS: Material Safety Data Sheets Are information sheets about specific chemicals. They describe the types of hazards, handling and clean up procedures, toxicity reports, manufacturing information. IUPAC: International Union of Pure and Applied Chemistry In order to achieve understanding scientists must communicate with each other and with the rest of the world. They must be able to communicate clearly and precisely using generalizations, theories, and scientific laws. When they communicate it should be international (meaning and symbols), precise, and as simple as possible (easily understood). The symbols and numbers on the periodic table are internationally accepted. Periodic table: a reference table that contains information on all the natural and manmade elements Empirical knowledge: knowledge obtained by our physical senses; something measureable Theoretical knowledge: comes from attempts to explain empirical knowledge Safe handling: Read, listen to, and follow all instructions carefully Wash your hands after each activity that uses chemicals Wear appropriate safety equipment, goggles and aprons, when handling hazardous chemicals Smell a substance by fanning the smell toward you with your hand. Do not put your nose over the substance 3 Do not taste anything Never pour liquids into containers in your hand Never use damaged glassware Clean up any spills immediately Never look into test tubes or containers from the top. Look through the sides Safe Storage: Label any container you put a chemical in Never store a chemical in damaged containers Oil based paints, gas, solvents, oil, herbicides should be stored in the garage Household cleaning supplies and plant fertilizers should be stored on a shelf out of reach of children Safe disposal: Follow instructions as to disposal of all chemicals Ask if you are unsure is a waste should be poured in the sink Unused prescription drugs should be returned to the pharmacist for proper disposal Oil and oil filters should be stored out of the house and used samples should be recycled and collected at a transfer site Paints, spray cans, pressurized containers go to the transfer station (toxic round up) Classification of Matter Matter: anything that has mass and occupies space. May be solid, liquid, or gas Mass: the quantity of matter present in a body. The mass of a body is constant and independent of its location. Pure substance: substances that donot breakdown into new elements or compounds. Their particles all have the same physical and chemical properties. They have a definite composition. Pure water, pure ethanol, pure oxygen, pure gold Compound: Two or more elements chemically bonded together. They can be separated chemically into simpler substances Ex. Water, ethanol, table sugar Element: Cannot be broken down into new elements/simpler substances. Each element is composed of only one type of atom. Ex. Oxygen, carbon, sodium, gold Homogeneous mixture: a mixture that has uniform composition. It looks like only one substance. The different components are not visible 4 Heterogeneous mixture: a mixture that does not have uniform composition (it has 2 or more parts to it, that can be seen). The different components are visible Alloy: a homogeneous mixture of two or more metals. Usually a solid Solution: a homogeneous mixture of substances that dissolve or mix evenly with each other. Usually a liquid Solute: the substance (usually a solid) that dissolves in a solvent forming a solution Solvent: the liquid that dissolves the solid in a solution Physical properties: those characteristics that can cause a physical change in a substance. They can be identified without reference to another substance. Ex. Boiling point, color, density, ductility, conductivity, magnetism, malleability, melting point, phase Physical change: this occurs when the matter changes but no new substances are produced. Ex. Phase changes: freezing/melting, boiling, condensing, sublimation Chemical properties: the chemical reactions that a substance can undergo Chemical change: this occurs when matter is changed to produce a new substance. The chemical and physical properties of the new substance will be different from the original substance. Ex. Burning is adding oxygen to a substance forming new gases. Evidence includes: gases, light, heat produced, color change, precipitate forms. Chemistry based careers in the community: Chemical Engineer, Cosmetology, Dietary nutritionist, pharmacist, food processing, and forensic police officer Historical examples of the use of chemical substances Clay used to make pots to hold water, bricks to build structures Sulfur: Latin for “burning stone”, historically called brimstone. Was used as an insecticide and for pyrotechnics in ancient Greece and Rome Iron used to make weapons in 1500 BC (Hittites) Copper first isolated about 9000 years ago, used for hammers, axes, containers Atomic Theories Dalton model Billiard ball model The atom was the smallest particle of matter It had no charges It was a solid sphere Thompson model The raisin bun model The atom was a solid sphere It had positive and negative charges on it 5 It was the smallest part of matter Rutherford Model The planetary model The atom was composed of a postive nucleus and separate negative electrons The electrons where orbiting the nucleus Bohr Model Electron energy level model Electrons occupy specific energy levels around the nucleus The first energy level holds only 2 electrons, the second 8, third 8, fourth 18, fifth 18 From this we draw energy level diagrams for the atomic structure of the first 20 elements Quantum Mechanics Model Electron cloud model Electrons travel between energy levels therefore there is only a “probability” of finding an electron in a given orbit at a given time. Atomic structure Nucleus: Central core of the atom Has all the mass Occupies very little volume Atoms are mostly empty space Composed of protons and neutrons Different atoms have different numbers of protons Protons Are part of the nucleus Have a positive charge Different elements are composed of atoms that have different numbers of protons The atomic number of an element equals the number of protons in the atoms of that element Neutrons Are part of the nucleus Have no charge Atoms with the same number of protons but different numbers of neutrons are called isotopes of that element The atomic mass is the sum of the mass of the neutrons and protons in the nucleus Nuclear Energy The protons and neutrons are held together by strong forces. The protons and neutrons are composed of smaller particles. Einstein discovered that the matter in the nucleus can change into energy 6 E=mc2 tells us how much energy matter can produce Nuclear reactions (fission and fusion) release tremendous amounts of energy Electrons Are found outside the nucleus, they orbit the nucleus They have a negative charge They are found in storage shelves called energy levels or orbitals For neutral atoms the number of protons equals the number of electrons which also equals the atomic number Atoms that gain or lose electrons are called ions Isotopes Atoms of the same element that have different numbers of neutrons There atomic masses are different They have the same number of protons therefore they are still the same element Ex. Carbon 14 has 6 protons, 8 neutrons Carbon 12 has 6 protons, 6 neutrons All metal atoms will lose electrons in chemical reactions to form positive ions, called cations. They will have more protons than electrons therefore have a positive charge All nonmetal atoms will gain electrons in chemical reactions to form negative ions, called anions. Ions Ionic compounds Made from metal and nonmetal Or metal and polyatomic ion Or two polyatomic ions Or polyatomic ion and nonmetal Must balance ions charges between species involved. They transfer electrons forming ionic bonds Use brackets around polyatomic ions Molecular compounds Made from two or more nonmetals Most formulas are memorized donot balance charges, they share electrons forming covalent bonds Acid compounds Are all formed from hydrogen compounds, are not molecular, neither ionic, but will form conducting solutions Most are memorized formulas and names Most are on the back of the periodic table Turn blue litmus paper red Have a pH of less than 7 Bases 7 Most are compound with hydroxides Are all ionic compounds and will form conductive solutions Turn red litmus paper blue Have pH of greater than 7 Chemical formulas Should always communicate three things: 1: the kind of atoms present using accepted symbols 2: the simplest ratio of atoms or ions given by the formula subscript 3: the physical state of the substance at STP, given by s, l, g, or aq. Chemical reaction and equations Illustrate the conservation of mass Mass of reactants must equal the mass of the products This is reflected in a balanced chemical equation Chemical equations are a simple, precise, and an international method of communicating information about a chemical reaction Reactants on left side, products on right side Both are separated by an arrow pointing to the reactants/left, not an equals sign Write correct formulas first, write states of matter next (s, l, g, or aq) Finally balance the equation without changing the chemical formulas Balancing equations Begin with the atom that has the biggest number (subscript) Determine the lowest common multiple between the reactant and the product Write this number as the coefficient for both these two elements/compounds Balance the remaining atoms using the same strategy The number of atoms of each element must be the same on both side of the equation. Reaction Types: Formation= E + E C Decomposition = C E + E Single Replacement = E + C E + C Double Replacement = C + C C + C Combustion = HC + Oxygen CO2 + H2O Evidence for Chemical reactions Color change Temperature change – Endothermic-feels cold – Exothermic-feels hot-may produce flames Gas produced (bubbles or fizzes) Light produced Precipitate forms-solution often goes cloudy Moles A quantity of items similar to a pair (2), dozen (12), gross (144), ream (500) One mole is 6.02 x 10 to the power 23 items 8 It is used only to measure amounts of atoms and molecules Molar Mass Is the mass of one mole of element or a compound Ex. Carbon is 12.01 grams per mole Molar mass for every element is on the periodic table Molar mass of compounds is determined by adding the sums of the molar masses of all the atoms in that compound We can convert from mass to moles or the reverse with a simple equation Mass = moles x molar mass m = n x M Moles = mass divided by molar mass n = m/M Endothermic reactions Energy is used by the reaction Products have more energy than the reactants The reaction temperature decreases The reaction “feels” cold Exothermic reactions Energy is given off by the reaction Less energy in the products than the reactants The reaction temperature increases The reaction “feels” warm or hot 9 Unit TWO: Physics 1. Analyze and illustrate how technologies based on thermodynamic principles were developed before the laws of thermodynamics were formulated a. illustrate, by use of examples from natural and technological systems, that energy exists in a variety of forms b. describe, qualitatively, current and past technologies used to transform energy from one form to another, and that energy transfer technologies produce measurable changes in motion, shape or temperature c. identify the processes of trial and error that led to the invention of the engine, and relate the principles of thermodynamics to the development of more efficient engine designs d. analyze and illustrate how the concept of energy developed from observation of heat and mechanical devices 2. Explain and apply concepts used in theoretical and practical measures of energy in mechanical systems a. describe evidence for the presence of energy; i.e., observable physical and chemical changes, and changes in motion, shape or temperature b. define kinetic energy as energy due to motion, and define potential energy as energy due to relative position or condition c. describe chemical energy as a form of potential energy d. define, compare and contrast scalar and vector quantities e. describe displacement and velocity quantitatively f. define acceleration, quantitatively, as a change in velocity during a time interval: g. explain that, in the absence of resistive forces, motion at constant speed requires no energy input h. recall, from previous studies, the operational definition for force as a push or a pull, and for work as energy expended when the speed of an object is increased, or when an object is moved against the influence of an opposing force i. define gravitational potential energy as the work against gravity j. relate gravitational potential energy to work done using Ep = mgh and W = Fd and show that a change in energy is equal to work done on a system k. quantify kinetic energy using Ek = 1/2 mv2 and relate this concept to energy conservation in transformations (e.g., for an object falling a distance “h” from rest: mgh = Fd = 1/2 mv2) l. derive the SI unit of energy and work, the joule, from fundamental units 10 m. investigate and analyze one-dimensional scalar motion and work done on an object or system, using algebraic and graphical techniques 3. Apply the principles of energy conservation and thermodynamics to investigate, describe and predict efficiency of energy transformation in technological systems a. describe, qualitatively and in terms of thermodynamic laws, the energy transformations occurring in devices and systems b. describe how the first and second laws of thermodynamics have changed our understanding of energy conversions c. define, operationally, “useful” energy from a technological perspective, and analyze the stages of “useful” energy transformations in technological systems d. recognize that there are limits to the amount of “useful” energy that can be derived from the conversion of potential energy to other forms in a technological device e. explain, quantitatively, efficiency as a measure of the “useful” work compared to the total energy put into an energy conversion process or device f. apply concepts related to efficiency of thermal energy conversion to analyze the design of a thermal device g. compare the energy content of fuels used in thermal power plants in Alberta, in terms of costs, benefits, efficiency and sustainability h. explain the need for efficient energy conversions to protect our environment and to make judicious use of natural resources Energy the capacity to do work It can cause changes in motion, shape, temperature, light It can cause physical or chemical changes Forms include: chemical, nuclear, geothermal, wind, solar, tidal, gravitational, kinetic, thermal, electrical, mechanical All forms of energy can be traced back to the sun. The original form of almost all energy on the earth is the sun. Forms of Energy Geothermal- heat in the earth produced by the radioactive breakdown of matter Tidal-movements of the ocean produced by gravitational attraction of the moon Solar-light from fusion reaction in the sun Wind-produced by differential light absorption and heating of the earth’s surface Energy conversion Technologies Windmills Hydroelectric dams 11 Gas/goal power stations Gas engine Steam engine Electric motor Solar cells Hydrogen fuel cell Energy Conversions Several things can happen as a result of energy converting from one form to another Change in motion Change in shape Change in temperature Change in light Engines An engine is a man made device that used combustion to convert one form of energy into another for a specific purpose (motion) The first engine was a steam engine. It used steam (thermal energy) to create mechanical energy (motion) Modern engines use hydrocarbons (gasoline or diesel or propane)—chemical energy to create mechanical energy (motion) Improvements in engines It required a better understanding of energy and the laws of thermodynamics to make better engines Any energy conversion produces waste heat. This will cause expansion of metal and excess friction, damaging parts. So ways of eliminating waste heat had to be incorporated into engine design (radiators, cooling systems, lubrication) this allowed engines to get bigger, run longer and produce more power Energy and the laws of thermodynamics The concept of energy developed from observations of heat and mechanical devices This lead to the laws of thermodynamics First law: Energy is always conserved; or energy in = energy out. You cannot get more than what you put in. Second law: No conversion is ever 100 % efficient. During any conversion there will always be waste heat produced. (You can never have a perpetual motion machine) Motion as a description of energy Energy involves the capacity to do work Work involves movement/motion Changes in motion are determined by changes in distance and time Changes in distance and time are measured as speed or velocity Speed The distance travelled by an object during a given time interval divided by the time interval. It is a scalar quantity; there is no direction described Distance time graphs 12 Describe motion of an object Distance is on the vertical (y) axis Time is on the horizontal (x) axis Straight line means uniform motion Slope of the line determines the magnitude of the speed Curved lines describe nonuniform motion: acceleration or deceleration Measurement in science Answers cannot be more precise than the least precise number used in the calculation Accuracy: how close you are to the target, the correct measurement, free from error Precision: how careful you were in making the measurement Significant digits Are those digits obtained from a properly taken measurement 1. 2. 3. Count all digits from 1 to 9 plus zeros in between and following another digits Do not count zeros in front of a value because they are only there to set the decimal place (they only tell us where the measurement started) Exact numbers are not uncertain and are said to have an infinite number of significant digits. Ex. Numbers that are defined/constants, and numbers that result from counting objects. Multiplication and division. When multiplying or dividing, multiply or divide, then round off the answer to the least number of significant digits of the numbers used in the calculation. Scientific notation Is a method of expressing values as a number between 1 and 10 multiplied by a power of 10. Do not use scientific notation unless required: 1. 2. For expressing the proper number of significant digits For making the value less cumbersome in written work or calculations. Scalar quantities: describe magnitude but not direction. Ex. Distance is a scalar quantity that describes the length of a path between two points or locations. Ex. Distance, time, speed Vector quantities: describe magnitude with direction. To distinguish these quantities symbols for vectors are written with arrows above them while symbols for scalars are not. Ex. Position, velocity, acceleration, displacement Displacement is a vector quantity that describes the straight line distance from one point to another as well as the direction. It is mathematically defined as the difference between two positions Position is a vector quantity that describes a specific point relative to a reference point 13 Velocity The displacement of an object during a time interval divided by the time interval. Displacement (and velocity) is a vector quantity. They describe an amount and a direction. Displacement describes the straight line distance from one point to another (not necessarily the total distance) as well as the direction. To Calculate displacement you need to know the beginning and final positions. Acceleration Not all objects move with uniform motion, constant speed or velocity Objects can slow down, speed up, stop or start moving The rate at which an objects motion changes is called acceleration Acceleration is the rate of change in velocity When objects slow down this is negative acceleration or deceleration Force A push or pull on an object The amount of force is affected by the size, or amount of the object (mass) and by the rate of movement of the object (acceleration) F = force (Newtons) m=mass (kilograms) a=acceleration (m/s2) F=mxa The units for force are called Newtons, named after the classical physicist Isaac Newton 1 Newton is the force required to move a 1 kilogram mass at 1m/s2, ignoring friction. Inertia is the property of an object to resist motion, or to stay in motion In the absence of resistive forces, motion at a constant speed requires no energy input Work The transfer of energy from one object to another The application of a force over a distance The object must move in order for work to be done W=work (joules) F=force (Newtons) d=distance (meters) W=Fxd Graphically, work is the total area below the line in a force vs distance graph Gravitational potential energy The stored energy in an object due to its distance above the surface of the Earth; work against gravity It takes more energy (work) to move an object higher above a surface. Thus the higher an object the more energy it will have and the more work it can do when it falls and collides with something on the way down Ep = gravitational potential energy m=mass (kilograms) g=accelerations due to gravity (9.81 m/s2) d=distance (m) Ep = m x g x d Work can be converted to potential energy and vice versa 14 W = F x d (substitute m x a for force) W = m x a x d = Ep Kinetic energy The energy of motion Is a function of the mass and velocity (speed) of the object Ek = ½ mv2 Ek= kinetic energy (Joules) m= mass (kilograms) v= velocity or speed (m/s) Mechanical energy The energy due to the motion and position of an object Em = Eg + Ek Energy is always conserved in any system therefore in any system potential energy of whatever form gets converted to kinetic energy (and other forms) and vice versa so the total energy always remains the same Laws of thermodynamics First Law: Also called the law of conservation of energy. Energy cannot be created or destroyed, but can be transformed from one form to another or transferred from one object to another. These transformations are called energy conversions/systems. Second Law: No process is ever 100% efficient. There will always be waste or unintended forms of energy released from any energy conversion, system, or process. Heat always flows from a hot object to a cold object. Perpetual motion machines can not exist Efficiency Efficiency = useful work output total work input x 100 useful work is the intended purpose of the device or activity nonuseful work is the unintended output from the device or activity. Efficiencies of modern devices Incandescent light bulb—5% Fluorescent light bulb– 20 % Gas engine—20% Electric motor– 50-90% Coal burning power plant Natural gas burning power plant Hydroelectric dam—90% Photovoltaic cells (solar panels) Need for efficiency Make judicious and prudent use of our natural resources Protect the environment: exploration and extraction damages, pollutants from combustion or manufacturing of materials for energy production 15 Unit THREE: Biology 1. Explain the relationship between developments in imaging technology and the current understanding of the cell 1. 2. 3. 4. 5. 6. 7. 8. describe how advancements in knowledge of cell structure and function have been enhanced and are increasing as a direct result of developments in microscope technology and staining techniques explain three advantages of using light microscopes outline the advantages of using electron microscopes List the properties of a light microscope and how to use the microscope Describe how to make a wet-mount slide and make drawings from the microscope identify areas of cell research at the molecular level state that a virus is a non-cellular structure consisting of DNA or RNA surrounded by a protein coat trace the development of the cell theory: all living things are made up of one or more cells and the materials produced by these, cells are functional units of life, and all cells come from pre-existing cells As the microscope has developed and improved so has our knowledge and understanding of the cell and its components. Better technologies have allow science to identify, describe, and explain cell organelles and the processes they control, such as cell division, respiration, photosynthesis, and transport mechanisms. Anton Van Leeuwenhoek: one of the first to build simple microscope and observe nature and draw what he saw. Robert Hooke: 1665, was the first to use the word “cell” to describe what he saw with microscopes of the time. Simple microscope: uses one lens placed in front of the object to magnify the light reflected from the object Compound microscope: uses at least two lenses (eyepiece and objective) to magnify the image. Light microscope: uses lenses to magnify the light reflected off an object Electron microscope: uses electrons to create an image seen on a monitor Scanning e.m.: bounces electrons off the surface (usually coated with a thin film of gold) of an object, creates a 3d image of the exterior of the object. Can only examine outside surface of objects, but with very high resolution and magnification. Transmission e.m.: sends electrons through the tissues/cells of a specimen, the scattering of the electrons is recorded by sensors and these create an image of the specimen. It views internal structure of cells with very high magnification and resolution. Binocular: two eyepieces (oculars) Advantages of light microscopes: Inexpensive, Can view live specimens, Simple specimen preparation Disadvantages of light microscopes: Can only magnify up to 4000x, Resolution decreases with increasing magnification 16 Advantages of electron microscopes: very high magnification, very high resolution Disadvantages of electron microscopes: expensive, require extensive training, only view dead tissue Properties of light microscopes a. b. c. d. Magnification: The light from an object is magnified as it goes through two primary lenses, the objective lens first, then the ocular lens, then it enters your eye. Our microscope have one ocular that magnifies 10 x and three different objective lenses that magnify 4x, 10x, and 40 x. Resolution: This is the sharpness or clarity of the image you see. As the magnification increase the resolution decreases. As the magnification increases you are looking at a smaller and smaller part of the object and the microscope gathers less and less light, thus the image appears fuzzier and darker (so you must turn up the light when using high magnifications) inversion: When light goes through a lens the image is flipped upside-down and backwards. This is called inversion. Objects seen through the light microscope are inverted. Top is bottom and left is right. field of view: This is the circular area you see when you look through the ocular. As magnification increases the diameter of the field of view decreases. As magnification increases you look at a smaller and smaller area of the object. Wet mount slide preparation 1. obtain small thin section of specimen and place on a clean slide 2. place a drop of water on the specimen 3. place a cover slip over the specimen starting at a 45 angle Staining slides 1. place one or two drops of stain on one edge of the cover slip, so the drop falls on the cover slip and the glass slide. 2. take a piece of paper towel and place it against the opposite edge of the cover slip. Allow the paper towel to absorb the water from under the cover slip Linear magnification of picture or drawing Pick on object in your field of view Estimate how many times that object will fit across the field of view Divide the field of view diameter by that number to approximate the size of the object, this is the actual size of the object Use a ruler to measure the same object in your drawing, this is the drawing size Drawing = Drawing size Mag Actual size Virus structure Are noncellular They are protein coat with genetic material inside Have no cell organelles (parts) They can only reproduce inside another living cell Cell theory 17 Developed by Schleiden, Schwann, and Virchow (mid 1800’s) 1. All organisms are composed of one or more cells 2. The cell is the smallest functional unit of life 3. All cells are produced from other cells 2. Describe the function of cell organelles and structures in a cell, in terms of life processes, and use models to explain these processes and their applications 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. describe the cell as a functioning open system that acquires nutrients, excretes waste, and exchanges matter and energy (A.P. Cells communicate by generating, transmitting, and receiving chemical signals) (A.P. Cells communicate with each other through direct contact with other cells or from a distance via chemical signaling) identify the structure and describe, in general terms, the function of the cell membrane, nucleus, lysosome, vacuole, mitochondrion, endoplasmic reticulum, Golgi apparatus, ribosomes, chloroplast and cell wall, where present, of plant and animal cells (A.P. DNA, and in some cases RNA, is the primary source of heritable information) (A.P. eukaryotic cells maintain internal membranes that partition the cell into specialized regions) (A.P. Archea and bacteria generally lack internal membranes and organelles and have a cell wall) compare the structure, chemical composition and function of plant and animal cells, and describe the complementary nature of the structure and function of plant and animal cells describe the role of the cell membrane in maintaining equilibrium while exchanging matter; identify functions of membrane proteins; fluid mosaic model, membrane proteins, other important membrane compounds describe how knowledge about semi-permeable membranes, diffusion and osmosis is applied in various contexts describe cell size and shape as they relate to surface area to volume ratio, and explain how that ratio limits cell size compare passive transport of matter by diffusion and osmosis with active transport in terms of the particle model of matter, concentration gradients, equilibrium and protein carrier molecules, protein pumps (A.P. Cell membranes separate the internal environment of the cell from the external environment) (A.P. Selective permeability is a direct consequence of the membrane structure, as describe by the fluid mosaic model) use models to explain and visualize complex processes like diffusion and osmosis, facilitated diffusion, endoand exocytosis, and the role of cell membrane in these processes (A.P. Viral replication results in genetic variation, and viral infection can introduce genetic variation into hosts) Cells: A functioning open system that acquires nutrients, excretes wastes, and exchanges matter and energy They communicate by cell to cell contact (immune cells) They communicate over distances using chemicals (neurotransmitters and hormones) Used for single celled or multicelled organisms In single celled organisms, signal transduction pathways influence how the cell responds to its environment. Some microbes use chemicals to communicate with other nearby cells and to regulate specific pathways in response to population density (quorum sensing) Cell Organelles Nucleus Chromosomes DNA RNA Plasmids 18 Centriole Mitochondria, cristae and matrix Chloroplast, grana, thylakoids, stroma, chlorophyll a Vacuole Golgi apparatus, cisternae Endoplasmic reticulum, rough and smooth Ribosome, ribosomal RNA and protein Lysosome, apoptosis Microtubules Flagella Cilia Plant vs Animal cells Plant cells: cell wall(cellulose), chloroplast, large vacuoles Animal cells, no cell wall, centrioles, small vacuoles Prokaryotic vs Eukaryotic Archaea and Bacteri generally lack internal membranes (membrane bound organelles) and have a cell wall Noneukaryotic organisms have circular chromosomes, while eukaryotic organisms have multiple linear chromosomes, some exceptions exist Prokaryotes, viruses and eukaryotes can contain plasmids Cell membranes: Fluid Mosaic Model The cell membrane can “pinch off” or be added to (forming vacuoles) giving it a dynamic/changing/fluid/flexible nature Mosaic comes from the proteins scattered throughout the membrane Phospholipid bilayer Phosphates on the outside, both sides, hydrophilic Lipid tails “sandwiched” on the inside, hydrophobic Integral proteins span the membrane, used as channels and for transport in and out. These make the membrane semipermeable; the membrane selects, by size, what particles can pass in and out. Peripheral proteins, usually embedded on the outside, used as identity markers and receptors Cholesterol, provides flexibility to membrane Carbohydrates, used as identity markers Glycoprotiens Glycolipids Membrane proteins also, Transport material in and out of the cell, Receive chemical signals, Recognition of other cells, perform Enzyme activity Phospholipids give the membrane both hydrophilic and hydrophobic properties. The hydrophilic phosphate portions of the phospholipids are oriented toward the aqueous external or internal environments, while the hydrophobic fatty acid portions face each other within the interior of the membrane itself. Embedded proteins can be hydrophilic, with charged and polar side groups, or hydrophobic, with nonpolar side groups. Small, uncharged polar molecules and small nonpolar molecules, such as N2, freely pass across the membrane. Hydrophilic substances such as large polar molecules and ions move across the membrane 19 through embedded channel and transport proteins. Water moves across membranes and through channel proteins called aquaporins. Cell walls provide a structural boundary, as well as a permeability barrier for some substances to the internal environments. Cell membrane transport mechanisms Passive transport: includes diffusion, osmosis, and factilitated diffusion. This is the primary way cell resources are imported and cell wastes are exported. No energy is required Nonpassive transport: include active transport, endocytosis, and exocytosis. These all require energy Diffusion The movement of particles from an area of high concentration to an area of low concentration Particles flow down the concentration gradient Does not require cellular energy Can occur across semipermeable membranes Osmosis is a special name for the diffusion of water Factors that affect the rate of diffusion Temperature - the faster the temp. the faster the diffusion Size of particles - larger particles will not diffuse due to the semipermeable nature of the membrane Concentration gradient - the larger the gradient the faster the rate of diffusion Concentration descriptors Isotonic – the concentrations are equal Hypertonic – the concentration is high, meaning the particle concentration is high compared to another solution Hypotonic – the concentration is low, meaning the particle concentration is low compared to another solution Particles always flow from high to low conc. By diffusion (from hyper to hypo) Water will flow from low to high particle conc. (from hypo to hyper) which still is from high to low water concentration Facilitated Diffusion Uses membrane proteins to move substances into or out of the cell, usually charged and polar molecules through a membrane. Does not use cellular energy Active Transport The movement of substances from an area of low conc. into an area of high conc. Uses transport proteins in the cell membrane Uses cellular energy Endocytosis There are two forms Phagocytosis or cell eating. The cell engulfs larger molecules into a vacuole. Pinocytosis or cell drinking. The cell engulf small molecules into a vesicle 20 Exocytosis The cell produces a waste, or a product produced by the cell, in a vacuole or vesicle and moves it out of the cell. Cell metabolism Viruses: Cells range in size from 1 um to 1 mm Most cells are very small The size of cells is limited by metabolism Metabolism refers to the chemical reactions and processes that go on in the cell to keep the cell alive In order for metabolism to be maintained nutrient must pass through the cell membrane to be used inside the cell. Cells can be affected by biotic and abiotic factors (temp, conc., light) The greater the volume of the cell the greater the metabolism needed to keep it alive. As cell size increases the volume increases faster than the surface area of the cell membrane. This creates a problem for larger cells. There comes a point when the surface area of a cell cannot supply nutrients fast enough for the demands of the volume of the cell. At this point the cell cannot grow any bigger Very large cells (fat cells) are just storage cells and have very slow metabolism. This surface area to volume relationship is what limits the size of cells Therefore cells cannot grow to be very big; they do not grow bigger than 1 mm. a. Viral replication differs from other reproductive strategies and generates genetic variation via various mechanisms. 1. Viruses have highly efficient replicative capabilities that allow for rapid evolution and acquisition of new phenotypes. 2. Viruses replicate via a component assembly model allowing one virus to produce many progeny simultaneously via the lytic cycle. 3. Virus replication allows for mutations to occur through usual host pathways. 4. RNA viruses lack replication error-checking mechanisms, and thus have higher rates of mutation. 5. Related viruses can combine/recombine information if they infect the same host cell. 6. HIV is a well-studied system where the rapid evolution of a virus within the host contributes to the pathogenicity of viral infection. b. The reproductive cycles of viruses facilitate transfer of genetic information. 1. Viruses transmit DNA or RNA when they infect a host cell. • Transduction in bacteria • Transposons present in incoming DNA 2. Some viruses are able to integrate into the host DNA and establish a latent (lysogenic) infection. These latent viral genomes can result in new properties for the host such as increased pathogenicity in bacteria. 3. Analyze plants as an example of a multicellular organism with specialized structures at the cellular, tissue and system levels 1. 2. explain why, when a single-celled organism or colony of single-celled organisms reaches a certain size, it requires a multicellular level of organization, and relate this to the specialization of cells, tissues and systems in plants explain and investigate the transport system in plants; i.e., xylem and phloem tissues and the processes of transpiration, including the cohesion and adhesion properties of water, turgor pressure and osmosis; 21 3. 4. 5. 6. diffusion, active transport and root pressure in root hairs, translocation of sugars and amino acids from source and sink. describe how the cells of the leaf system have a variety of specialized structures and functions; i.e., epidermis including guard cells, palisade tissue cells, spongy tissue cells, and phloem and xylem vascular tissue cells to support the process of photosynthesis explain and investigate the gas exchange system in plants; i.e. guard cells, stomata and the process of diffusion explain and investigate phototropism and gravitropism as examples of control systems in plants, trace the development of theories of phototropism and gravitropism (A.P. Signal transmission within and between cells mediates gene expression; ex. Seed germination and gibberellin) multicelluarity and cell specialization in plants single cells must Must carry out all functions necessary for life Ex. Breathing, excretion, food intake, communication, reproduction Ex. Paramecium, euglena, bacteria Specialization Cells in multicelled organisms are specialized to perform certain functions by expressing some of their genes but not others. Consequently many of these cells lose some of the other processes that single celled organisms can do. Ex. Muscle cells contract, have many mitochondria, but cannot divide. Ex. Red blood cells transport gases but have no nucleus There are over 200 different cells types in humans Multicelled organisms show emergent properties These properties arise from the interaction of component parts. The whole is greater than the sum of the parts No one part/tissue/cell can produce this property but working together with other cells/tissues/organs this property emerges. Ex. Consciousness/self awareness is a property of the human brain produced by the interaction of nerve cells in the organ called the brain. Ex. Circulation of blood is a property of the heart and blood vessels Plant tissues/ parts Leaf: location for photosynthesis Stem: supports leaves off the ground, connects leaves to roots Roots: anchor the plant, obtain water and nutrients for leaves Vascular tissue: cells that transports nutrients and water inside the plant, between roots and leaves. Xylem hollow dead cells that transport water and minerals, phloem living cells that transport sugars. Meristematic tissue (meristem)—is the growth tissue in a plant Apical meristems-growth from the ends of stems (terminal buds and axillary buds). Causes elongation of roots or stems Lateral meristems- growth inside the stem or root that causes it to get wider. Roots stems and leaves can be modified to perform other functions Leaves: Bulbs for food storage and tendrils for climbing Stem: tubers for food storage and tendrils for climbing 22 Roots: food storage Leaf parts: Cuticle Epidermis Palisade layer Spongy layer(mesophyll) Guard cells Stomata Veins/vascular tissue water transport in plants (cohesion tension theory) Water evaporates from the leaves through stomata, called transpiration Leaf cells replace water by osmosis from xylem Causes a pull of water to the leaf (water cohesion) Water travels (transpiration pull) through the dead, hollow, xylem cells Cohesion and adhesion are due to hydrogen bonding (polarity) of water molecules Flow of water is a continuous stream (transpiration stream) due to cohesion of water to itself and adhesion to the xylem cell walls Transpiration: the loss of water from a plant, most often through the stomata in the leaf. The plant hormone abscisic acid causes guard cells to close the stomata. Plants produce abscisic acid when they lack water. For abiotic factors affect the rate of water loss/transpiration: Light: guard cells close stomata during darkness, during day water loss is greater Temperature: increasing temperature increases evaporation Humidity: the lower the humidity the faster the loss of water Wind: increases water loss by removing saturated air from the surface of the leaf mineral ion transport Active transport of mineral ions into the root hairs creates a hypertonic environment in the root hair cells The movement of water also carries with it dissolved minerals, called mass flow This also creates high water pressure in the roots Branching of roots and roots hairs increase surface area of the root allowing for enhanced water and mineral ion uptake Control of growth Phototropism: Growth in response to light 23 Light rays hit the plant stem Light causes the plant hormone auxin to migrate to the opposite side (shady side) Auxin stimulates cell division The shady side of the stem grows faster than the light side causing the stem to bend toward the light Photoperiodism: The response to change in length of the night, that results in flowering in long-day and short-day plants Gravitotropism: Growth in response to gravity Roots always grow down regardless of how the seed is placed Seed germination: Seed absorbs water Giberellin activates the gene that produces amylase Amylase digests starch in cotelydon, producing glucose Glucose is used for energy for cell division/growth happens (leaf, stem, root) 24 Unit FOUR: Biosphere 1. Describe how the relationships among input solar energy, output terrestrial energy and energy flow within the biosphere affect the lives of humans and other species a. explain how climate affects the lives of people and other species, and explain the need to investigate climate change b. identify the Sun as the source of all energy on Earth c. analyze, in general terms, the net radiation budget, using per cent; i.e., solar energy input, terrestrial energy output, net radiant energy d. describe the major characteristics of the atmosphere, the hydrosphere and the lithosphere, and explain their relationship to Earth’s biosphere e. describe and explain the greenhouse effect, and the role of various gases—including methane, carbon dioxide and water vapour—in determining the scope of the greenhouse effect Biosphere: 1. 2. 3. 4. 5. Another name for the surface of the earth; it is composed of all parts that sustain life It is composed of 3 divisions The atmosphere: the layer of air around the earth The hydrosphere: the water (marine and freshwater) on the surface of the earth The lithosphere: the land surface not covered by water Atmosphere: 1. 2. 3. 4. 5. is composed of 78% nitrogen gas, 21% oxygen gas, and less than 1% argon, carbon dioxide, and numerous other gases is divided into several layers, from the bottom up they are: troposhere, stratosphere, ionosphere, and magnetosphere the stratosphere (15-50 km) contains the important gas ozone, composed of 3 atoms of oxygen whereas oxygen gas is only 2 atoms of oxygen. The ozone layer is concentrated around 15-30 km above the earths surface Ozone absorbs harmful UV-b radiation preventing most of this radiation from reaching the surface of the earth. There are 3 types of UV radiation: UV-a is least harmful and not blocked out by the atmosphere, UV-b is more harmful causing skin cancer in increased exposure, and UV-c the most damaging radiation, which is totally blocked out by the upper layers of the atmosphere. Over the last 40-50 years chloroflorocarbons, produced as a propellant for aerosol cans (spray cans and bottles) has been destroying the ozone layer. UV light in the upper atmosphere decomposes CFC’s releasing the chlorine atom. This atom will react with ozone, breaking ozone into normal oxygen which does not block out the UV-b radiation. In the late 1980’s and international ban on CFC’s has slowly had a levelling off effect on the rate of ozone depletion. 25 The carbon cycle and the greenhouse effect 2. 3. 4. 5. Carbon dioxide is produced during fossil fuel combustion Carbon dioxide allows light to pass through but traps reflected heat. This is the greenhouse effect The greenhouse effect keeps the earth warm and allows life to exist. But too much carbon dioxide can increase global temp too fast. This can cause melting of glaciers and icecaps, increasing the level of the ocean, flooding coastal cities, increased storms, hurricanes, tornadoes, and shifts in global weather and climate Hydrosphere: 1. 2. 3. 4. 5. 6. Water covers nearly 75% of the surface of the earth Most of this water is marine, or saltwater. Of the freshwater the majority is locked as ice in the polar ice caps water makes up 70-99% of all living things it is the major compound in living cells needed for digestion, transport, cooling, location where reactions occur Lithosphere: 1. 2. 3. 4. The land mass of the earth covers about 25% of the surface of the earth Much of this land mass is not liveable by humans (deserts, icecaps, mountain ranges) The areas of the lithosphere where life exists are divided into regions called Biomes characterized by dominant vegetation and associated animal species. Two major life sustaining processes occur here, and in the oceans. Photosynthesis and cell respiration. (write chemical reactions) Energy Flow in Global systems 1. 2. 3. 4. 5. 6. 7. 8. 9. energy used to sustain life in the biosphere mostly comes in the form of light from the sun. is generated by fusion reactions in the sun where two hydrogen atoms fuse to form one helium atom. In the process there is a loss of mass. The mass is converted into energy according to Einstein’s famous equation E=mc2 The energy released is in the form of the electromagnetic spectrum (gamma, UV, visible, infrared, radio, TV, ) the sun is too far away to feel any heat, plus the vacuum of space prevents heat from being transmitted through space the visible light reaches the outer atmosphere and from here down to the earth surface it gets reflected and absorbed by different parts of the biosphere is reflected by the upper atmosphere, scattered by the atmosphere and clouds, absorbed by the surface, absorbed by oceans and used for wind and waves, absorbed by plants for photosynthesis, reflected by the surface (lithosphere) Ultimately all energy received by the earth is reradiated back into space in the form of heat. The energy the earth receives over the long term always balances the energy it gives off. This satisfies the first law of thermodynamics. The second law of thermodynamics states that when energy is converted from one form to another the conversion is never 100% efficient. Much of the energy is lost as heat. This is the heat radiated from the atmosphere, lithosphere, and hydrosphere. Overall energy always flow through a system, it drives the system. It may be temporarily stored, and given off later, it may be changed from one form to another, but it is never lost. Energy flows, which in turn causes matter to cycle and life to exist Examples of conversions that release heat are decomposition and muscle contractions The suns energy produces life on earth through the processes of photosynthesis and cell respiration. Less than 1% of the energy that reaches the biosphere is used for photosynthesis. This is the energy that is transferred through all food chains and food webs. It is the energy that is inside every cell of every living organism. 26 2. Analyze the relationships among net solar energy, global energy transfer processes—primarily radiation, convection and hydrologic cycle—and climate. a. describe, in general terms, how thermal energy is transferred through the atmosphere (i.e., global wind patterns, jet stream, Coriolis effect, weather systems) and through the hydrosphere (i.e., ocean currents, large bodies of water) from latitudes of net radiation surplus to latitudes of net radiation deficit, resulting in a variety of climatic zones b. investigate and describe, in general terms, the relationships among solar energy reaching Earth’s surface and time of year, angle of inclination, length of daylight, cloud cover, albedo effect and aerosol or particulate distribution c. explain how thermal energy transfer through the atmosphere and hydrosphere affects climate d. investigate and interpret how variations in thermal properties of materials can lead to uneven heating and cooling e. investigate and explain how evaporation, condensation, freezing and melting transfer thermal energy; i.e., use simple calculations of heat of fusion Hfus= n Q and vaporization Hvap= n Q , and Q=mct to convey amounts of thermal energy involved, and link these processes to the hydrologic cycle 1. 2. 3. 4. 5. 6. The energy that reaches the earth’s surface is not always evenly distributed. Variables such as cloud cover, latitude, and albedo influence the amount of solar radiation that part of the earth receives. This results in differences in weather and climate at different times of the year in different locations. Latitude - the position on the Earth relative to the equator. The location on the Earth determines the angle of incoming solar radiation and therefore the amount of light absorbed, and heat given off, at that latitude. The latitude of an area on the earth will also influence how much solar radiation that area receives at different times of the year. The earth is tilted on its axis approximately 23 degrees. As the earth orbits around the sun this tilt causes the northern hemisphere (as compared to the southern hemisphere) to be more exposed to the direct rays of the sun for half of the year and then when the earth is in the opposite side of its orbit the northern hemisphere will be less exposed to the direct rays of the sun for the other half of the year. This variation causes a warming trend in the Northern Hemisphere, our spring and summer during march to august, and a cooling trend, our fall and winter during September to February. We know these as the seasons. The opposite pattern exists in the Southern Hemisphere. The surface feature of the land often influences how much energy is absorbed. The term used to describe the amount of light reflected off a surface (hence the amount of energy it absorbs) is Albedo. The higher the albedo of a surface the less light and energy it absorbs (it reflects more light and is brighter or shinier). An example is a snow covered field vs an unplanted, dark soil surface. The snow has a high albedo, it reflects a lot of light, therefore it absorbs very little light, absorbing less energy and heating up slower. The dark field, however, reflects very little light, absorbing most of the light it receives, absorbing more energy and heating up faster. This creates “thermals” over dark fields. Thermals are areas of rising air currents created by warmer, less dense air. Birds, especially predators, are often seen flying/gliding over/in these thermals; the rising air keeps them aloft with very little wing flapping on the part of the bird. Clouds have high albedo, consequently the surface below the clouds does not receive as much light as an area with fewer clouds. Climate- the prevailing weather conditions of a place as determined by temperature, precipitation, wind, clouds, and sunlight over a period of years. 27 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. Weather- the general conditions of the atmosphere at a particular time and place. Ex. Temperature, precipitation, wind, clouds sunlight. Weather systems are driven by the energy from the sun. Both latitude and surface features on the Earth affect weather and climate. Thermal energy transfer through the atmosphere: global wind patterns, jet stream, Coriolis effect, weather systems Currents in the oceans and atmosphere distribute the solar heating from the tropics to the higher latitudes. Oceans: act as heat sinks. They store large amounts of thermal energy preventing the earth from getting to hot, but also release this energy preventing the earth from getting too cold. Ocean currents: once heated the surface water can be mixed downward or can be moved across by wind. Surface ocean currents are created by surface wind and their directions are influenced by land masses. Global wind patterns: are produced by heating at the earth’s surface. The surface heating causes convection (the circulation and distribution of air). Warm air rises (is less dense) and cold air falls (is more dense). Areas of cool air form high pressure systems that push air (wind) to areas of lower pressure or warm air. Weather systems: large air masses of similar air conditions (weather) are created by heating of the ocean. The air above the ocean warms by conduction and convection creating the air mass. These will move in response to wind patterns and the rotation of the earth. Coriolis effect: The rotational movement of the air masses and currents on the earth produced by the rotation of the earth. The effect is most evident in large systems and is very difficult to produce in small scale systems. Air masses rotate clockwise in the northern hemisphere and counterclockwise in the southern hemisphere. Jet stream: currents of extremely fast moving air about 10-15 km above the earth’s surface. They move in a west to east directions because this is the direction the earth spins. Friction between the earth and the atmosphere at ground level pulls the air in the direction of rotation. Gulf Stream: a 100 km wide “river” of ocean water that starts in the Caribbean and goes to Newfoundland. It follows the east coast of North America El Nino: a global weather change caused by warm ocean currents moving in different directions than normal. Ex. Warm pacific water moves north along the west coast of North America creating warmer than usual air masses in the western U.S and Canada. Unique properties of water influence climate High heat capacity: Large amounts of energy are needed to change the temperature of water compared to other substances. Large bodies of water such as oceans and large lakes have a moderating effect on the air temperature of nearby land communities. Water temperatures change slowly and by small amounts. Large bodies of water absorb a large amount of light and heat during the day and during the summer, but release the heat slowly at night and during the winter. Phase changes: Water has high heat of vaporization. This is the energy needed to convert water from a liquid to a gas. The temperature of the water does not change. For water to evaporate a large amount of energy is needed to break the attractive forces among water molecules. The opposite occurs during condensation. For water to form a liquid, it must lose a lot of energy to allow enough molecules to come together and form bonds or attractive forces to pull the molecules closer to each other. Water evaporates when the molecules absorb enough heat to have sufficient kinetic energy to break loose from their neighbouring molecules. This heat can be absorbed from sunlight, from air at the water’s surface, or from other water molecules. When heat is absorbed from other water molecules, they lose energy and cool. This is known as evaporative cooling and it causes bodies of water to remain at a relatively stable temperature. When it rains the clouds release this energy causing a slight warming of the air. Water has high heat of fusion. This is the energy released to convert water from a liquid state to a solid state (freezing). When water freezes it releases thermal energy, the temperature of the water does not change. When water melts it absorbs thermal energy but the temperature does not change. In spring, the days become linger 28 and the sun begins to warm the land (the sun rises higher off the horizon, more direct sunlight). If large amounts of snow and ice remain from the winter, then much of the suns energy is used to melt them. Therefore, the air temperature does not rise as much as it would in the absence of snow and ice. As winter sets in, the days get shorter and the sun provides less heat than in summer. As liquid water freezes, however, it releases heat. Therefore, the air temperature does not drop as much as it would if there were no water to freeze. Thermal Energy Also called internal energy The total kinetic of all the particles in a substance The sum of all the vibrations and of the particles Units for energy are in Joules (J) Kinetic Energy Is the energy of motion Is the translational (shaking/vibration) or rotational motion of the particles Potential Energy Is stored energy Produced or stored in the forces between the molecules that determine the state of matter It is the forces that hold the molecules together in that state Temperature The average kinetic energy of the particles in a substance Different systems are used to measure temperature. These systems are called temperature scales There are three different scales: Celsius, Kelvin, Fahrenheit Kelvin Scale: (K) there are no negative temperatures, zero is the lowest. This is the point at which there is no more motion of the particles; no kinetic energy (0 degrees K). Water freezes at 273 K, boils at 373 K. Celcius: The lowest temperature is -273 C, water freezes at 0 C and boils at 100 C K = C + 273 Heat Is the transfer of thermal (internal) energy Is measured in Joules (J) When there is a difference in temperature between two locations thermal energy (heat) will transfer. The faster movement of particles in one area will bump into the slower moving particles in the other area, speeding the slow up and slowing fast particles down. Heat always travels from a hot area to a cold area until it reaches thermal equilibrium Thermal equilibrium occurs when there is no net transfer of heat, when the two areas are at the same temperature (all their particles are vibrating with the same speed. Conduction The transfer of thermal energy due to the collision of particles (no net movement of substance) Solids are good conductors b/c particles are more tightly bound allowing for easier collisions. Metals are the best b/c electrons are more mobile Convection 29 The movement of fluid particles from warmer areas to cooler areas Occurs best in liquids and gases b/c the particles are more free to move among themselves Radiation The transfer of energy in a wavelike form It does not require a medium to travel through Calculating Thermal Energy Is a function of three variables: Mass, the amount of matter present, the more matter the more energy Temperature, how fast all the matter or particles are vibrating Specific heat capacity. The amount of heat (thermal energy) it takes to increase the temperature of 1.0 g of a substance by 1 degree C Different substances have different “c”. They have different types and numbers of particles that take different amounts of energy to move. Units are J/gC . Ex. Pure water 4.19, aluminum .903, copper 3.85, lead .130 Q = mc ∆ t Q = thermal energy in Joules or kilojoules m= mass in g or kg c= specific heat capacity ∆ t = the change in temp, in Celsius Heat of fusion Also called specific latent heat of fusion The amount of heat required to melt 1 g of a substance. Units are J/g Heat of vaporization for water = 2260 J/g This is also the heat given off if the substance freezes. Q = m Hfus Heat of vaporization Also called specific latent heat of vaporization The amount of heat required to evaporate 1.0 g of a substance. Units are J/g This is also the amount of heat given off when a substance condenses, Q= mHvap Heat of fusion for water = 334 J/g 3. Relate climate to the characteristics of the world’s major biomes, and compare biomes in different regions of the world a. describe a biome as an open system in terms of input and output of energy and matter and exchanges at its boundaries b. relate the characteristics of two major biomes (i.e., grassland, desert, tundra, taiga, deciduous and rain forest) to net radiant energy, climatic factors (temperature, moisture, sunlight and wind) and topography (mountain ranges, large bodies of water) 30 c. analyze the climatographs of two major biomes (i.e., grasslands, desert, tundra, taiga, deciduous and rain forest) and explain why biomes with similar characteristics can exist in different geographical locations, latitudes and altitudes d. identify the potential effects of climate change on environmentally sensitive biomes Biomes: The biosphere contains many types of ecosystems. The can be divided into terrestrial (land) and aquatic (water) ecosystems. Terrestrial ecosystems are also called biomes Tundra Taiga Temperate deciduous rain forest Tropical rain forest Grassland Desert Polar regions Immediately south of tundra Midway between poles and equator Equatorial Midway between poles and equator Middle to equatorial Very little, mostly snow 35-40 cm/yr snow, rain,fog 100 cm/yr snow and rain 200 and more cm/yr 25-75 cm/yr Less than 25 cm/yr Low, below zero Zero to +5 Warmer than taiga +20-+25 Similar to forest but dryer Hot during day cold at night Shrubs, low flowering plant, no trees Coniferous trees, shrubs, lichens Coniferous and deciduous trees, flowering plants Lots of trees and flowering plants, dense vegetation Mostly grasses, some trees, some shrubs Cactus, very little vegetation Rodents, hares, caribou Bison, hare, moose, wolves, bear Insects, birds, deer, squirrels Insects, birds, reptiles, amphibians, primates Snakes, burrowing animals, coyotes Reptiles, insects, birds. Factor Location Precipitation Avg. Annual temperature plants animals Climatograms One method of illustrating this variation in energy absorption is through climatograms. A climatogram is a two in one graph that illustrates the average monthly precipitation and temperature of a given location. The precipitation is illustrated as a bar graph while the temperature is illustrated as a line graph. Temperature curves that are higher in the middle of the graph (July and August) are associated with northern hemisphere countries while the 31 opposite is for southern hemisphere countries. Temperature lines that are relatively flat (constant temperature year round) indicate a tropical location while the steeper the line the more polar the location. Amounts of precipitation provide an indication of the dominant vegetation that will be found in the location. Consequently, this provides information about the general types of animals that could be found in the location. 4. Investigate and interpret the role of environmental factors on global energy transfer and climate change a. investigate and identify human actions affecting biomes that have a potential to change climate and critically examine the evidence that these factors play a role in climate change b. identify evidence to investigate past changes in Earth’s climate c. describe and evaluate the role of science in furthering the understanding of climate and climate change through international programs d. describe the role of technology in measuring, modelling and interpreting climate and climate change e. describe the limitations of scientific knowledge and technology in making predictions related to climate and weather f. assess, from a variety of perspectives, the risks and benefits of human activity, and its impact on the biosphere and the climate Climate change: a change in the average atmospheric conditions in an area. Most often this refers to global climate change, but is most often measured in location changes in the patterns of weather over prolonged periods of time. Most often measured in changes in average temperatures in the different seasons, changes in rainfall amounts and distribution, ocean temperatures and different depths, ice depth and range of glaciers and polar icecaps. Generally most scientists agree that the earth is very slowly warming up. There are some scientists who disagree and argue that it will be cooling down over the next 100 years. Role of technology in Climate Change Ice core samples: atmospheric gases are trapped in ice as glaciers are produced. Analysis of these gases provides information about carbon dioxide and other gas concentrations in the atmosphere hundreds of thousands of years ago, depending on how old the ice sample is. Pollen samples: Pollen are reproductive cells from plants. Finding pollen in soil and ice samples from thousands of years ago provides information about the types and abundance of plants that grew in an area. The plants that grow in an area indicate the climate of that area at that time. Computer models: Use past data from weather and climate patterns to predict future weather and climate, both short term (tomorrows weather) and long term (climate change of the earth) Satellite imagery: Determines the temperature, concentration of gases in the atmosphere, tracks storms development and movement, tracks ocean current and air current movements. Limitations of scientific knowledge and predictions about weather and climate Weather and climate are influenced by many large and small scale factors simultaneously, this requires a lot of information to be processed simultaneously, it is a very complex system. 32 Computer models do not have all the information because we do not fully understand all factors involved Predictions and conclusions drawn from models are not 100% reliable. Short term predictions of weather are more reliable (have greater confidence) but long term predictions of weather are not as reliable. Long term predictions of climate are generally accurate because climate is a general description. Predictions of climate change and how much change will happen are not as accurate because of the complexity of the system Human Activity and its impact on the Biosphere and Climate Human Activity Risks Benefits Combustion of fossil fuels Increased greenhouse effect and increased global warming Jobs for people in communities, more money for countries for health care and education. Loss of ecosystems Creates business, economic growth Species extinction Damage to cities and human made structures Deforestation Loss of ecosystems Lumber to be sold Species extinction Crops to harvest Increased global warming Creates jobs Soil erosion and damage to aquatic ecosystems Money for countries for health and education Factors Causing Climate Change and Change in Biomes and Aquatic Ecosystems Environmental factors: Continental drift (geological events/processes) The continents are slowly moving. This causes changes in ocean currents, air currents and precipitation patterns. This also causes different amounts of light to be absorbed at different latitudes. These changes result in a different distribution of thermal energy over the biosphere. Solar cycles The sun produces different amount of light in its lifetime affecting the amount of light received by the Earth. Meteors and volcanic eruptions These produce large amounts of dust and gas that can enhance the greenhouse effect. Oceans Absorb and release greenhouse gases thus influencing the greenhouse effect 33 Earth’s Tilt This varies between 22 and 24 degrees over a 100,000 year cycle. This can affect the amount of light absorbed at different latitudes and the amounts of thermal energy produced at those latitudes. Human Factors: Fossil fuel combustion Humans are adding large amounts of greenhouse gases by burning fossil fuels (coal, oil, natural gas). Carbon dioxide concentration in the atmosphere has increased 31% since 1750. Deforestation Clear cutting and burning large amounts of forest adds dust and carbon dioxide to the atmosphere. But this also reduces the earth’s ability to remove carbon dioxide from the atmosphere. Trees, and all other plants, perform photosynthesis which removes carbon dioxide from the atmosphere. Evidence for past changes in Earth’s climate Gases trapped in glacier ice (hundreds of thousands of years old) tell us the concentration of gases in the atmosphere during that time period Pollen samples in fossils and plant fossils in old rocks tell us what vegetation was in that area during that time period. The vegetation tells us indirectly what the climate was like then Tree rings reflect the growth of the tree in the growing season (summer) Examining old trees (thousands of years) we can determine how warm the climate has been in the recent past 34 35