Downloaded 21 times
Uploaded byStephanie Beck
AP Bio Ch. 1-3
This document provides an overview of introductory biology and basic chemistry concepts. It discusses the scope of biology, the diversity and unity of life, evolution as biology's unifying theme, the building blocks of matter including atoms and molecules, chemical bonding, inorganic and organic molecules, and the unique properties of water that support life. Key points include that biology studies life at all levels, all organisms share DNA, evolution occurs through natural selection, atoms are made of protons, neutrons and electrons, chemical bonds form molecules, and the polarity and hydrogen bonding of water molecules gives it properties like cohesion, surface tension, and the ability to moderate temperature.
More Related Content
AP Bio Ch. 1-3
- 1. Intro to Biologyand Basic Chemistry Ch. 1,2,3
- 2. We are livingin a golden age of biology Biology is woven into the fabric of society as never before Knowledge of biological concepts is more important than ever
- 3. Biology isthe scientific study of life THE SCOPE OF BIOLOGY Biology’s scope stretches across the enormous diversity of life on Earth
- 4. Biologists explorelife at levels ranging from the biosphere to the molecules that make up cells Figure 1.2.2 Cells Nucleus within cell Cells in squirrel DNA
- 5. The Unity ofLife Amoebas, molds, trees, and people are all made from similar cells All organisms share a common chemical language for their genetic material, DNA
- 6. Diversity isthe hallmark of life Life in Its Diverse Forms •The diversity of known life includes 1.7 million species •Estimates of the total diversity range from 5 million to over 30 million species
- 7. Biodiversity canbe both beautiful and overwhelming Grouping Species: The Basic Concept Taxonomy is the branch of biology that names and classifies species It formalizes the hierarchical ordering of organisms Figure 1.7
- 8. The threedomains of life are The Three Domains of Life Bacteria Archaea Eukarya Figure 1.8.1 Domain Bacteria Domain Archaea Domain Eukarya Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia
- 9. Bacteria andArchaea are both prokaryotic domains Figure 1.8.2 Domain Bacteria Domain Archaea
- 10. Eukarya includes at leastfour kingdoms Protista Plantae Fungi Animalia Figure 1.8.3 Domain Eukarya Kingdom Protista Kingdom Plantae Kingdom Fungi Kingdom Animalia
- 11. Quick Think Whatare the 2 classifications of prokaryotes? All eukaryotes belong to which group? Can you list the characteristics of the prokaryotic domain Archaea?
- 12. Underlying the diversityof life is a striking unity, especially at the lower levels of structure Unity in the Diversity of Life Example: the universal genetic language of DNA Evolution accounts for this combination of unity and diversity
- 13. The universalarchitecture of eukaryotic cilia Figure 1.9 (a) Paramecium (b) Cells from fallopian tube (c) Cross section of cilium
- 14. Think-Pair-Share What is studied underthe scope of biology? Think/Write 30 seconds Pair 1 minute Share with class when asked to
- 15. The historyof life is a saga of a restless Earth billions of years old EVOLUTION: BIOLOGY’S UNIFYING THEME Fossils document this history Figure 1.10
- 16. Life evolves Eachspecies is one twig of a branching tree of life extending back in time Figure 1.11 Giant panda Spectacled bear Sloth bear Sun bear American black bear Asiatic black bear Polar bear Brown bear Ancestral bear
- 17. The evolutionary viewof life came into focus in 1859 when Charles Darwin published The Origin of Species The Darwinian View of Life Figure 1.12
- 18. Darwin’s bookdeveloped two main points Descent with modification Natural selection
- 19. Darwin wasstruck by the diversity of animals on the Galápagos Islands Natural Selection He thought of adaptation to the environment and the origin of new species as closely related processes As populations separated by a geographic barrier adapted to local environments, they became separate species
- 20. Fourteen species of Galápagos fincheshave beak shapes adapted to suit their environments Medium ground finch Cactus ground finch Small tree finch Medium tree finch Woodpecker finch Large ground finch Small ground finch Large cactus ground finch Vegetarian finch Large tree finch Mangrove finch Green warbler finch Gray warbler finch Sharp-beaked ground finch Seed-eaters Cactus-flower -eaters Bud-eater Insect-eaters Ground finches Tree finches Warbler finches Common ancestor from South American mainland Figure 1.13
- 21. Darwin synthesizedthe concept of natural selection from two observations that were neither profound nor original Darwin’s Inescapable Conclusion Others had the pieces of the puzzle, but Darwin could see how they fit together Darwin & Wallace
- 22. Fact 1:Overproduction and struggle for existence Fact 2: Individual variation The inescapable conclusion: Unequal reproductive success It is this unequal reproductive success that Darwin called natural selection The product of natural selection is adaptation
- 23. Natural selection isthe mechanism of evolution Figure 1.14 Population with varied inherited traits Elimination of individuals with certain traits Reproduction of survivors Increasing frequency of traits that enhance survival and reproductive success 1 2 3 4
- 24. Artificial selectionis the selective breeding of domesticated plants and animal by humans Observing Artificial Selection Figure 1.15
- 25. There aremany examples of natural selection in action Observing Natural Selection The development of antibiotic-resistant bacteria is one Figure 1.16
- 26. Darwin’s publicationof The Origin of Species fueled an explosion in biological research Evolution is one of biology’s best demonstrated, most comprehensive, and longest lasting theories Evolution is the unifying theme of biology
- 27. Think-Pair-Share How would you explain evolutionand natural selection to someone (briefly)?
- 28.
- 29. The Chemistry of Life Take any biological system apart and you eventually end up at the chemical level Ecosystem African savanna Community All organisms in savanna Population Herd of zebrasOrganism Zebra Organ system Circulatory system Organ Heart Cell Heart muscle cell Tissue Heart muscle tissue Molecule DNA Atom Oxygen atom
- 30. Building Blocks ofMatter Matter is the amount of material in an object; it is measured using mass (not weight!)
- 31. Matter is composedof chemical elements There are 92 naturally occuring elements 25 are essential to life Four of these make up ~ 96% of the weight of the human body Trace elements occur in smaller amounts
- 32. Trace elements arealso essential for life Trace elements are required for all organisms in very small amounts Iron is essential to all organisms Iodine is essential to vertebrates An iodine deficiency causes goiter
- 33. Atoms: smallest unit ofmatter that retains its characteristics -ex. H, C, Na Nucleus = protons and neutrons Electrons = in clouds around the nucleus, at varying energy levels
- 34. The type ofatom is determined by the number of protons in its nucleus. Atomic Number •the number of protons in the nucleus What is the atomic number of carbon? Mass Number • the sum of the protons and neutrons What is the mass number of carbon? Atomic Elements
- 35. Isotopes arealternate mass forms of an element Isotopes They have the same number of protons and electrons But they have a different number of neutrons Change in # of neutrons changes the mass number
- 36. Radioactive isotopes Thenucleus decays, giving off particles and energy Radioactive isotopes have many uses in research and medicine Example: PET scans
- 37. Electrons determinehow an atom behaves when it encounters other atoms The properties of an atom are determined by the configuration of its outer electrons (aka valence electrons) Electron Arrangement and the Chemical Properties of Atoms
- 38. Stable Electron Configuration Themost stable electron configuration is 8 in the outer shell (2 for H and He) All elements will try to gain, lose or share outer electrons in order to reach this configuration.
- 39. Electrons tend toexist at the lowest state of potential energy - the lowest shell 1st shell - holds 2 electrons max 2nd shell - holds up to 8 electrons 3rd shell - holds up to 8 electrons
- 40. Shell Relationships Elements withthe same number of valence electrons tend to behave similarly
- 41. Atoms ofthe four elements most abundant in life Figure 2.7 Electron First electron shell (can hold 2 electrons) Outermost electron shell (can hold 8 electrons) Carbon (C) Atomic number = 6 Nitrogen (N) Atomic number = 7 Oxygen (O) Atomic number = 8 Hydrogen (H) Atomic number = 1
- 42. Energy Emission Energy mayhit an electron and raise it to a higher level This is an unstable condition The electron emits energy as it drops down to original level
- 43. Think-Pair-Share What is anatom, what are the parts of an atom, and which of these parts is most important to reactivity and why?
- 44. Chemical Bonding and Molecules Chemical reactions enable atoms to give up or acquire electrons in order to complete their outer shells These interactions usually result in atoms staying close together The atoms are held together by chemical bonds
- 45. When anatom loses or gains electrons, it becomes electrically charged Ionic Bonds Charged atoms are called ions Cations - positive charge Anions - negative charge Sodium atom (Na) Chlorine atom (Cl) Complete outer shells Sodium ion (Na+ ) Chloride ion (Cl− ) Sodium chloride (NaCl)
- 46.
- 48. Ionic Bonds Ionicbonds are formed between oppositely charged ions Ionic compounds are salts Salts do not consist of individual molecules • They are just an aggregate of cations and anions
- 49. A covalentbond forms when two atoms share one or more pairs of outer-shell electrons Covalent Bonds
- 50. Cells constantlyrearrange molecules by breaking existing chemical bonds and forming new ones Chemical Reactions Such changes in the chemical composition of matter are called chemical reactions Hydrogen gas Oxygen gas Water Reactants Products
- 51. Chemical reactionscan be symbolized with equations On the left side of the equation are the reactants, the starting materials On the right side of the equation are the products, the end materials
- 52. Balancing Equations Amountof matter on both sides of a chemical reaction must stay the same Matter cannot be created or destroyed Numbers (coefficients) are added in front of chemical formulas to BALANCE equations. 2NaOH + H2SO4 2H2O + Na2SO4
- 53. Molecules Formed fromatoms that “share” their electrons (covalent bonding) Together they have a neutral charge Often contain carbon and are then known as “organic” molecules Can have single, double or triple bonding
- 54.
- 55. Organic Molecules Mustinclude Carbon atom(s)
- 56.
- 57. Think-Pair-Share Why do we saythat matter cannot be created or destroyed?
- 58.
- 59. Your Objective Be ableto state at least 1 property of water that helps support life AND Be able to explain how the chemical nature of water gives rise to that property
- 60. Water and Life Lifeon Earth began in water and evolved there for 3 billion years. Modern life still remains tied to water Cells are composed of 70%- 95% water
- 61. •Water is foundWateris found as a liquid overas a liquid over 71% of the71% of the earthearth •The abundanceThe abundance of water is aof water is a major reasonmajor reason Earth isEarth is habitablehabitable
- 62. Studied inisolation, the water molecule is deceptively simple Its two hydrogen atoms are joined to one oxygen atom by single covalent bonds The structure of water H O H
- 63. But theelectrons of the covalent bonds are not shared equally between oxygen and hydrogen This unequal sharing makes water a polar molecule Oxygen is more electronegative than hydrogen, so it has a greater pull on the electrons (+) (+) (−) (−)
- 64. The polarityof water results in weak electrical attractions between neighboring water molecules These interactions are called hydrogen bonds (b) (−) Hydrogen bond (+) (+) (−) (−) (+) (+) (−)
- 65.
- 66.
- 67. Quick Think Whyis a molecule of water said to have polar covalent bonds? What kind of bonds hold individual water molecules together?
- 68. Water’s Life Supporting Properties The polarity of water molecules and the hydrogen bonding that results explain most of water’s life-supporting properties Water’s cohesive nature Water’s ability to moderate temperature Floating ice Versatility of water as a solvent
- 70. Water molecules sticktogether as a result of hydrogen bonding The Cohesion of Water This is called cohesion Cohesion is vital for water transport in plants Microscopic tubes
- 72. Surface tension isthe measure of how difficult it is to stretch or break the surface of a liquid Hydrogen bonds give water an unusually high surface tension Cohesion between water molecules form a skin-like surface Can support animals like “waterCan support animals like “water striders” in pondsstriders” in ponds
- 73. Surface Tension Waterdrops are round because all the molecules on the edge are pulled to the middle.
- 74. Adhesion Water willalso adhere to other polar substances This is called adhesion It is due to the polar nature of the water molecule Caused by adhesion the water runs along the glass and does not fall straight.
- 75. Capillary Action Glasshas polar molecules. Glass can hydrogen bond. Attracts the water molecules. Some of the pull is up.
- 76. Meniscus Water curvesup along the side. This makes the meniscus.
- 77. Quick Think Howare adhesion and cohesion similar and different? Give an example of how these properties help support life.
- 78. Water moderates temperature Because of hydrogen bonding, water has a strong resistance to temperature change
- 79. Water moderates temperature Heat and temperature are related, but different Heat is a measure of the amount of kinetic energy in the atoms and molecules in something Temperature measures the intensity of the heat Whenever 2 objects meet, the cooler object absorbs heat from the warmer object until they are the same temperature
- 80. Water moderates temperature Water has a high specific heat Specific heat = the amount of heat that mustSpecific heat = the amount of heat that must be absorbed or lost to change thebe absorbed or lost to change the temperature of 1g of the substance 1° Ctemperature of 1g of the substance 1° C
- 81. Water moderates temperature Since water has a high specific heat, it will not change temperature much when it absorbs or loses heat This is because much of the absorbed heat is used to break hydrogen bonds, not increase the kinetic energy of the molecules
- 82. Water moderates temperature So water can absorb and store large amounts of heat while only changing a few degrees in temperature
- 83. Large bodies ofwater help to moderate temperature Earth’s giant water supply causes temperatures to stay within limits that permit life Evaporative cooling removes heat from the Earth and from organisms
- 84. How water moderates temperature Wateralso has:Water also has: High heat of fusionHigh heat of fusion • The temp at which liquid turns solidThe temp at which liquid turns solid High heat of vaporizationHigh heat of vaporization • The temp at which liquid turns to gasThe temp at which liquid turns to gas
- 85. When watermolecules get cold, they move apart, forming ice The Biological Significance of Ice Floating A chunk of ice has fewer molecules than an equal volume of liquid water IceLiquid water
- 86. The densityof ice is lower than liquid water This is why ice floats Figure 2.15 Hydrogen bond Liquid water Hydrogen bonds constantly break and re-form Ice Stable hydrogen bonds
- 87.
- 88. Dipole Structure Icefloats in water because all ice molecules are held in hexagons Center is open space, making ice 8% less dense than water.
- 89. Since icefloats, ponds, lakes, and even the oceans do not freeze solid Marine life could not survive if bodies of water froze solid
- 90. Floating iceinsulates water below, preventing freezing: critical for ocean animals
- 91. Maximum density: 3.98o C Below this temp, form hexagonal polymers and decrease density Above this, molecules are energetic, water behaves like other liquids - expanding when warm and contracting when cool
- 92. A solutionis a liquid consisting of two or more substances evenly mixed Water as the Solvent of Life The dissolving agent is called the solvent The dissolved substance is called the solute Ion in solution Salt crystal
- 93. When wateris the solvent, the result is called an aqueous solution Water is a good solvent because it is polar Ionic (salts) and polar (sugars) compounds dissolve readily in water
- 94. Solvent Properties Waterdissolves salts by surrounding the atoms in the salt molecule and neutralizing the ionic bond holding the molecule together
- 95. Quick Think What aresome unique properties of water that allow it to support life and how is this related to its polar nature?
- 96.
- 97. Acid Acids, Bases, andpH A chemical compound that donates H+ ions to solutions Base A compound that accepts H+ ions and removes them from solution or a compound that dissociates in water to form hydroxide ions
- 98. Basic solution Neutral solution Acidic solution Oven cleaner Household bleach Householdammonia Milk of magnesia Seawater Human blood Pure water Urine Tomato juice Grapefruit juice Lemon juice; gastric juice pH scale To describe the acidity of a solution, we use the pH scale
- 99. pH scale (logscale) Each number on the scale is 10x difference from the number next to it • pH 1 is 10x more acidic than pH 2, 100x more acidic than pH 3, 1000x more acidic that pH 4, and so on
- 100. pH - PercentHydronium A measure of the percent of hydronium ions in the solution The greater the percent hydronium ions, the more acidic the solution is HH22COCO33 -------------> H-------------> H++ ++ HCOHCO33 -- CARBONIC ACIDCARBONIC ACID HYDRONIUM BICARBONATEHYDRONIUM BICARBONATE IONION IONION
- 101.
- 103. Buffers aresubstances that resist pH change They accept H+ ions when they are in excess They donate H+ ions when they are depleted Buffering is not foolproof Example: acid precipitation normal rain water (pH of 5-6) pH of acid rain is between 3-4
- 104. Buffers Dissolved CO2in water acts as a buffer, a substance that prevents large shifts in pH. Buffers help keep pool and spa water clean
- 105. Buffer Systems CO2 +H2O ←→ H2CO3 ←→ H+ + HCO3 - ←→ H+ + CO3 -2 H2CO3 is carbonic acid, H+ is the hydronium ion HCO3 - is the bicarbonate ion CO3 -2 is the carbonate ion
- 106. Buffer Systems CO2 +H2O ←→ H2CO3 ←→ H+ + HCO3 - ←→H+ + CO3 -2 Adding CO2 shifts the reaction to the right and produces more H+ ions making the water more acid.
- 107. Buffer Systems CO2 +H2O ←→ H2CO3 ←→ H+ + HCO3 - ←→ H+ + CO3 -2 Removing CO2 shifts the reaction to the left, combining H+ ions with carbonate and bicarbonate ions reducing the acidity.
- 108.