Chapter 6 bdol ic


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Chapter 6 bdol ic

  1. 1. Unit 1: What is Biology?Unit 2: EcologyUnit 3: The Life of a CellUnit 4: GeneticsUnit 5: Change Through TimeUnit 6: Viruses, Bacteria, Protists, and FungiUnit 7: PlantsUnit 8: InvertebratesUnit 9: VertebratesUnit 10: The Human Body
  2. 2. Unit 1: What is Biology? Chapter 1: Biology: The Study of LifeUnit 2: Ecology Chapter 2: Principles of Ecology Chapter 3: Communities and Biomes Chapter 4: Population Biology Chapter 5: Biological Diversity and ConservationUnit 3: The Life of a Cell Chapter 6: The Chemistry of Life Chapter 7: A View of the Cell Chapter 8: Cellular Transport and the Cell Cycle Chapter 9: Energy in a Cell
  3. 3. Unit 4: Genetics Chapter 10: Mendel and Meiosis Chapter 11: DNA and Genes Chapter 12: Patterns of Heredity and Human Genetics Chapter 13: Genetic TechnologyUnit 5: Change Through Time Chapter 14: The History of Life Chapter 15: The Theory of Evolution Chapter 16: Primate Evolution Chapter 17: Organizing Life’s Diversity
  4. 4. Unit 6: Viruses, Bacteria, Protists, and Fungi Chapter 18: Viruses and Bacteria Chapter 19: Protists Chapter 20: FungiUnit 7: Plants Chapter 21: What Is a Plant? Chapter 22: The Diversity of Plants Chapter 23: Plant Structure and Function Chapter 24: Reproduction in Plants
  5. 5. Unit 8: Invertebrates Chapter 25: What Is an Animal? Chapter 26: Sponges, Cnidarians, Flatworms, and Roundworms Chapter 27: Mollusks and Segmented Worms Chapter 28: Arthropods Chapter 29: Echinoderms and Invertebrate Chordates
  6. 6. Unit 9: Vertebrates Chapter 30: Fishes and Amphibians Chapter 31: Reptiles and Birds Chapter 32: Mammals Chapter 33: Animal BehaviorUnit 10: The Human Body Chapter 34: Protection, Support, and Locomotion Chapter 35: The Digestive and Endocrine Systems Chapter 36: The Nervous System Chapter 37: Respiration, Circulation, and Excretion Chapter 38: Reproduction and Development Chapter 39: Immunity from Disease
  7. 7. The Life of a Cell The Chemistry of Life A View of the Cell Cellular Transport and the Cell Cycle Energy in a Cell
  8. 8. Chapter 6 The Chemistry of Life 6.1: Atoms and Their Interactions 6.1: Section Check 6.2: Water and Diffusion 6.2: Section Check 6.3: Life Substances 6.3: Section CheckChapter 6 SummaryChapter 6 Assessment
  9. 9. What You’ll Learn You will relate an atom’s interactions with other atoms to its structure. You will explain why water is important in life. You will compare the role of biomolecules in organisms.
  10. 10. Section Objectives:• Relate the structure of an atom to the identity of elements.• Relate the formation of covalent and ionic chemical bonds to the stability of atoms.
  11. 11. Section Objectives:• Distinguish mixtures and solutions.• Define acids and bases and relate their importance to biological systems.
  12. 12. Elements• Everything – whether it is a rock, frog, or flower – is made of substances called elements.• An element is a substance that can’t be broken down into simpler chemical substances.
  13. 13. Natural elements in living things• Of the naturally occurring elements on Earth, only about 25 are essential to living organisms.• Carbon, hydrogen, oxygen, and nitrogen make up more than 96 percent of the mass of a human body.
  14. 14. Trace elements• Trace elements such as iron and copper, play a vital role in maintaining healthy cells in all organisms.• Plants obtain trace elements by absorbing them through their roots; animals get them from the foods they eat.
  15. 15. Table 6.1 Some Elements That Make Up the Human Body Percent By Percent By Element Symbol Mass in Element Symbol Mass in Human Body Human BodyOxygen O 65.0 Iron Fe traceCarbon C 18.5 Zinc Zn traceHydrogen H 9.5 Copper Cu traceNitrogen N 3.3 Iodine I traceCalcium Ca 1.5 Manganese Mn tracePhosphorus P 1.0 Boron B tracePotassium K 0.4 Chromium Cr traceSulfur S 0.3 Molybdenum Mo traceSodium Na 0.2 Cobalt Co traceChlorine Cl 0.2 Selenium Se traceMagnesium Mg 0.1 Fluorine F trace
  16. 16. Atoms: The Building Blocks of Elements• An atom is the smallest particle of an element that has the characteristics of that element.• Atoms are the basic building blocks of all matter.
  17. 17. The structure of an atom• The center of an atom is called the nucleus (NEW klee us).• All nuclei contain positively charged particles called protons (p+).• Most contain particles that have no charge, called neutrons (n0).
  18. 18. The Structure of an atom• The region of space surrounding the nucleus contains extremely small, negatively charged particles called electrons (e-) • This region ofNucleus space is referred to as an electronElectron cloud.energylevels
  19. 19. The Structure of an atom• Because opposites attract, the negatively charged electrons are held in the electron cloud by the positively charged nucleus.
  20. 20. NucleusElectron energy levels 8 protons (p+) 8 neutrons (n0)• Electrons exist around the nucleus in regions known as energy levels. Oxygen atom• The first energy level can hold only two electrons. The second level can hold a maximum of eight electrons. The third level can hold up to 18 electrons.
  21. 21. Electron energy levels• Atoms contain equal numbers of electrons and protons; therefore, they have no net charge.
  22. 22. Isotopes of an Element• Atoms of the same element always have the same number of protons but may contain different numbers of neutrons.• Atoms of the same element that have different numbers of neutrons are called isotopes (I suh tophs) of that element.
  23. 23. Compounds and Bonding• A compound is a substance that is composed of atoms of two or more different elements that are chemically combined.• Table salt(NaCl) is acompoundcomposed of the elements sodium and chlorine.
  24. 24. How covalent bonds form• Atoms combine with other atoms only when the resulting compound is more stable than the individual atoms.• For many elements, an atom becomes stable when its outermost energy level is full.• Sharing electrons with other atoms is one way for elements tobecome stable.
  25. 25. How covalent bonds form• Two hydrogen atoms can combine Hydrogen molecule with each other by sharing their electrons.• Each atom becomes stable by sharing its electron with the other atom.
  26. 26. How covalent bonds form Click image to view movie.
  27. 27. How covalent bonds form• The attraction of Hydrogen molecule the positively charged nuclei for the shared, negatively charged electrons holds the atoms together.
  28. 28. How covalent bonds form• A covalent bond holds the two hydrogen atoms together.• A molecule is a group of atoms held together by covalent bonds. Water It has no overall molecule charge.
  29. 29. How ionic bonds form• An atom (or group of atoms) that gains or loses electrons has an electrical charge and is called an ion. An ion is a charged particle made of atoms.• The attractive force between two ions of opposite charge is known as an ionic bond.
  30. 30. Chemical Reactions• Chemical reactions occur when bonds are formed or broken, causing substances to recombine into different substances.• All of the chemical reactions that occur within an organism are referred to as that organism’s metabolism.
  31. 31. Chemical Reactions
  32. 32. Writing chemical equations• In a chemical reaction, substances that undergo chemical reactions, are called reactants.• Substances formed by chemical reactions, are called products.
  33. 33. Writing chemical equations• A molecule of table sugar can be represented by the formula: C12H22O11.• The easiest way to understand chemical equations is to know that atoms are neither created nor destroyed in chemicalreactions. They are simply rearranged.
  34. 34. Mixtures and Solutions• A mixture is a combination of substances in which the individual components retain their own properties.• Neither component of the mixture changes.
  35. 35. Mixtures and Solutions• A solution is a mixture in which one or more substances (solutes) are distributed evenly in another substance (solvent).• Sugar molecules in a powdered drink mix dissolve easily in water to form a solution.
  36. 36. Acids and bases• Chemical reactions can occur only when conditions are right.• A reaction may depend on: - energy availability - temperature - concentration of a substance - pH of the surrounding environment
  37. 37. Acids and bases• The pH is a measure of how acidic or basic a solution is.• A scale with values ranging from below 0 to above 14 is used to measure pH.More acidic Neutral More basic
  38. 38. Acids and bases• Substances with a pH below 7 are acidic. An acid is any substance that forms hydrogen ions (H+) in water.• A solution is neutral if its pH equals seven.More acidic Neutral More basic
  39. 39. Acids and bases• Substances with a pH above 7 are basic. A base is any substancethat forms hydroxideions (OH-) in water. pH 11
  40. 40. Question 1Which of the following is an element?A. chlorophyllB. carbonC. sodium chlorideD. water
  41. 41. The answer is B. An element cant be brokendown into simpler chemical substances.Chemical elements combine in different waysto form a variety of substances useful to livingthings.
  42. 42. Table 6.1 Some Elements That Make Up the Human Body Percent By Percent By Element Symbol Mass in Element Symbol Mass in Human Body Human BodyOxygen O 65.0 Iron Fe traceCarbon C 18.5 Zinc Zn traceHydrogen H 9.5 Copper Cu traceNitrogen N 3.3 Iodine I traceCalcium Ca 1.5 Manganese Mn tracePhosphorus P 1.0 Boron B tracePotassium K 0.4 Chromium Cr traceSulfur S 0.3 Molybdenum Mo traceSodium Na 0.2 Cobalt Co traceChlorine Cl 0.2 Selenium Se traceMagnesium Mg 0.1 Fluorine F trace
  43. 43. Question 2The smallest particle of an element that has thecharacteristics of that element is a(n)__________.A. proton C. nucleusB. electron D. atom
  44. 44. The answer is D. Atoms are the basic buildingblocks of all matter and have the same generalstructure, including a nucleus and electrons.Elements found in both living and nonlivingthings are made of atoms. Nucleus An atom has a nucleus and electrons inElectron energy levels energy levels.
  45. 45. Question 3Which of the following can contain two types ofparticles?A. nucleusB. protonsC. neutronsD. electrons
  46. 46. The answer is A. The nucleus is the center ofthe atom and may contain both positivelycharged particles and particles that have nocharge. Nucleus 8 protons (p+) 8 neutrons (n0) Oxygen atom
  47. 47. Question 4Sodium and chlorine combine to form tablesalt. What do you know to be true?A. Sodium and chlorine are sharing electrons in their outer energy levels.B. Sodium and chlorine atoms have no overall electrical charge.
  48. 48. Question 4Sodium and chlorine combine to form tablesalt. What do you know to be true?C. Sodium and chlorine are less stable in the compound sodium chloride.D. Sodium and chlorine atoms in table salt have full outer energy levels.
  49. 49. The answer is D. Sodium and chlorineatoms combine because the resultingcompound, table salt, is more stable thanthe individual atoms. Sodium loses anelectron in its outer energy level, chlorinegains that electron in its outer energylevel, and an ionic bond is formed.
  50. 50. Section Objectives• Relate water’s unique features to polarity.• Identify how the process of diffusion occurs and why it is important to cells.
  51. 51. Water and ItsImportance• Water is perhaps the most important compound in living organisms.• Water makes up 70 to 95 percent of most organisms.
  52. 52. Water is Polar• Sometimes, when atoms form covalent bonds they do not share the electrons equally. This is called a polar bond.
  53. 53. Water is Polar• A polar molecule is a molecule with an unequal distribution of charge; that is, each molecule has a positive end and a negative end.• Water is an example of a polar molecule.• Water can dissolve many ionic compounds, such as salt, and many other polar molecules, such as sugar.
  54. 54. Water is Polar• Water molecules also attract other water molecules. Hydrogen atom• Weak hydrogen bonds are formed Hydrogen atom between positively charged hydrogen atoms and negatively charged oxygen atoms. Oxygen atom
  55. 55. Water resists temperature changes• Water resists changes in temperature. Therefore, water requires more heat to increase its temperature than do most other common liquids.
  56. 56. Water expands when it freezes• Water is one of the few substances that expands when it freezes.• Ice is less dense than liquid water so it floats as it forms in a body of water.
  57. 57. Early observations: Bownian motion• In 1827, Scottish scientist Robert Brown used a microscope to observe pollen grains suspended in water. He noticed that the grains moved constantly in little jerks, as if being struck by invisible objects.• This motion is now called Brownian motion.• Today we know that Brown was observing evidence of the random motion of atoms and molecules.
  58. 58. The process of diffusion• Diffusion is the net movement of particles from an area of higher concentration to an area of lower concentration.• Diffusion results because of the random movement of particles (Brownian motion).• Three key factors—concentration, temperature, and pressure—affect the rate of diffusion.
  59. 59. The results of diffusion• When a cell is in dynamic equilibrium with its environment, Material moving out of cell equals materials move into material moving into cell and out of the cell at equal rates. As a result, there is no net change in concentration inside or outside the cell.
  60. 60. Diffusion in living systems• The difference in concentration of a substance across space is called a concentration gradient.• Ions and molecules diffuse from an area of higher concentration to an area oflower concentration, moving with thegradient.• Dynamic equilibrium occurs when there is no longer a concentration gradient.
  61. 61. Question 1Explain why water is important to livingorganisms.AnswerLiving organisms must have water for lifeprocesses, because critical molecules and ionsmust be free to move and collide, which onlyhappens when they are dissolved in water.Water also transports materials in livingorganisms, such as in blood or sap.
  62. 62. Question 2 + Positively charged endHow doeswaters chemicalstructure impactits role in livingorganisms? + ― Negatively charged end
  63. 63. Because water is polar, it can dissolve manyionic compounds and polar molecules. Waterhas the property of capillary action that enablesplants to get water from the ground. Water alsoresists temperature changes, which allows cellsto maintain homeostasis.
  64. 64. Question 3Which of the following best describes diffusion?A. slow process resulting from random movement of particlesB. net movement of particles from area of low concentration to area of high concentration
  65. 65. Question 3Which of the following best describes diffusion?C. rapid process that is unaffected by increases in temperatureD. net movement of particles from high to low concentrations that accelerates when pressure decreases
  66. 66. The answer is A. Diffusion is a slow processresulting from the random movement ofparticles, and is the net movement of particlesfrom areas of high concentration to areas oflower concentration.
  67. 67. Section Objectives:• Classify the variety of organic compounds.• Describe how polymers are formed and broken down in organisms.• Compare the chemical structures of carbohydrates, lipids, proteins, and nucleic acids, and relate their importance to living things.• Identify the effects of enzymes.
  68. 68. The Role of Carbon in Organisms• A carbon atom has four electrons available for bonding in its outer energy level. In order to become stable, a carbon atom forms four covalent bonds that fill its outer energy level.
  69. 69. The Role of Carbon in Organisms• Two carbon atoms can form various types of covalent bonds—single, double or triple. Single Bond Double Bond Triple Bond
  70. 70. Molecular chains• Carbon compounds vary greatly in size.• When carbon atoms bond to each other, they can form straight chains, branched chains, or rings.
  71. 71. Molecular chains• Small molecules bond together to form chains called polymers. A polymer is a large molecule formed when many smaller molecules bond together.
  72. 72. The structure of carbohydrates• A carbohydrate is a biomolecule composed of carbon, hydrogen, and oxygen with a ratio of about two hydrogen atoms and one oxygen atom for every carbon atom.
  73. 73. The structure of carbohydrates• The simplest type of carbohydrate is a simple sugar called a monosaccharide (mah noh SA kuh ride). (ie. glucose, fructose)• The largest carbohydrate molecules are polysaccharides, polymers composed of many monosaccharide subunits. (ie. potatoes, liver)
  74. 74. The structure of lipids• Lipids are large biomolecules that are made mostly of carbon and hydrogen with a small amount of oxygen. (ie. fats, oils, waxes)• They are insoluble in water because their molecules are nonpolar and are not attracted by water molecules.
  75. 75. The structure of proteins• A protein is a large, complex polymer composed of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur.
  76. 76. The structure of proteins• The basic building blocks of proteins are called amino acids.• There are about 20 common amino acids that can make literally thousands of proteins.
  77. 77. The structure of proteins• Peptide bonds are covalent bonds formed between amino acids.
  78. 78. The structure of proteins• Proteins are the building blocks of many structural components of organisms.
  79. 79. The structure of proteins• Enzymes are important proteins found in living things. An enzyme is a protein that changes the rate of a chemical reaction.• They speed the reactions in digestion of food.
  80. 80. The structure of nucleic acids• A nucleic (noo KLAY ihk) acid is a complex biomolecule that stores cellular information in the form of a code.• Nucleic acids are polymers made of smaller subunits called nucleotides.
  81. 81. The structure of nucleic acids• Nucleotides are arranged in three groups—a nitrogenous base, a simple sugar, and a phosphate group. Phosphate Sugar Nitrogenous base
  82. 82. The structure of nucleic acids• DNA, which stands for deoxyribonucleic acid is a nucleic acid. Phosphate Sugar Nitrogenous base
  83. 83. The structure of nucleic acids• The information coded in DNA contains the instructions used to form all of an organism’s enzymes and structural proteins.• Another important nucleic acid is RNA, which stands for ribonucleic acid. RNA is a nucleic acid that forms a copy of DNA for use in making proteins.
  84. 84. Question 1How many covalent bonds does a carbon atomneed to form in order to become stable?A. 1B. 2C. 3D. 4
  85. 85. The answer is D. A carbon atom has fourelectrons available for bonding in its outerenergy level and needs to form four covalentbonds in order to become stable.
  86. 86. Question 2A __________ is a biomolecule composed ofcarbon, hydrogen, and oxygen with a ratio ofabout two hydrogen atoms and one oxygenatom for every carbon atom.A. carbohydrate C. proteinB. lipid D. fatty acid
  87. 87. The answer is A. Lipids are made mostly ofcarbon and hydrogen, and proteins containnitrogen in addition to carbon, hydrogen andoxygen.
  88. 88. Question 3In which type of molecule will you find peptidebonds?A. carbohydrate C. proteinB. lipid D. fatty acid
  89. 89. The answer is C. Amino acids are the basicbuilding blocks of proteins and are linkedtogether by peptide bonds.
  90. 90. Question 4What biomolecule is represented in thisdiagram? Phosphate Sugar Nitrogenous baseA. carbohydrate C. proteinB. nucleotide D. lipid
  91. 91. The answer is B. Nucleotides are the smallersubunits that make up nucleic acids. Nucleotidesare composed of three groups: a nitrogenousbase, a simple sugar, and a phosphate group. Phosphate Sugar Nitrogenous base
  92. 92. Question 5Describe an enzyme and its function.
  93. 93. An enzyme is a protein that enables othermolecules to undergo chemical changes to formnew products. Enzymes increase the speed ofreactions that would otherwise proceed tooslowly. Substrate Active site
  94. 94. Atoms and Their Interactions• Atoms are the basic building block of all matter.• Atoms consist of a nucleus containing protons and usually neutrons. The positively charged nucleus is surrounded by rapidly moving, negatively charged electrons.• Atoms become stable by bonding to other atoms through covalent or ionic bonds.
  95. 95. Atoms and Their Interactions• Components of mixtures retain their properties.• Solutions are mixtures in which the components are evenly distributed.• Acids are substances that from hydrogen ions in water. Bases are substances that form hydroxide ions in water.
  96. 96. Water and Diffusion• Water is the most abundant compound in living things.• Water is an excellent solvent due to the polar property of its molecules.• Particles of matter are in constant motion.• Diffusion occurs from areas of higher concentration to areas of lower concentration.
  97. 97. Life Substances• All organic compounds contain carbon atoms.• There are four principal types of organic compounds, or biomolecules, that make up living things: carbohydrates, lipids, proteins, and nucleic acid.• The structure of a biomolecule will help determine its properties and functions.
  98. 98. Question 1What is the difference between a compoundand an element?AnswerA compound is a substance that is composedof atoms of two or more different elementsthat are chemically combined. An element isa substance that cant be broken down intosimpler chemical substances.
  99. 99. Question 2What is it called when atoms share electrons? Water moleculeA. covalent bonding C. hydrogen bondingB. ionic bonding D. diffusion
  100. 100. The answer is A.Covalent bonds differfrom ionic bonds inthat the sharedelectrons move aboutthe nuclei of bothatoms of the covalent Watercompound. molecule
  101. 101. Question 3Which of the following combinations willproduce a solution?A. chocolate chips and cookie doughB. sand and sugar crystalsC. powdered drink mix and waterD. oil and vinegar
  102. 102. The answer is C. Allof the combinationsare mixtures because Water moleculesthe individualcomponents retain Sugar moleculestheir own properties. Asolution is a mixture in Sugar crystalwhich one or moresubstances is dissolvedin another and will notsettle out of solution.
  103. 103. Question 4 What type of substance forms hydrogen ions in water? A. enzymeB. acid C. base D. polar
  104. 104. The answer is B. Any substance that formshydrogen ions (H+) in water is an acid. ThepH of a substance is a measure of how acidicor basic a solution is.
  105. 105. Question 5Which of the following best describes amolecule with an unequal distribution ofcharge?A. polarB. acidicC. basicD. diffuse
  106. 106. The answer is A. Each polar molecule has apositive end and a negative end. Polar watermolecules attract ions and other polarmolecules, and can dissolve many ioniccompounds.
  107. 107. Question 6Name the chemical reaction illustrated in thediagram. CH2OH O CH2OH O A. hydrolysisGlucose OH OH HO OH HO OH OH + B. condensation + O H2O O O HOCH2Fructose HO OH HOCH2 HO C. Protein OH CH2OH OH CH2OH synthesis Sucrose D. glycolysis
  108. 108. The answer is B. In condensationreactions, small molecules bond togetherto produce a polymer and water. CH2OH CH2OH O O Glucose OH OH HO OH HO OH OH + O + H2O HOCH2 O OH HOCH2 O Fructose HO HO CH2OH CH2OH OH OH Sucrose
  109. 109. Question 7 An oxygen atom has 8 protons and 8 neutrons. How many electrons does it have? A. 8 B. 18C. 32D. 0
  110. 110. The answer is A. Atoms contain equalnumbers of electrons and protons and have nonet charge. Nucleus 8 protons (p+) 8 neutrons (n0) Oxygen atom
  111. 111. Question 8Based on your CH2OH A. nuclease Oknowledge ofbiomolecules, HO OH B. lipasewhich of the OHfollowing O C. pepsinsubstances HOCH2 O D. waterwould be mosteffective at HO CH2OHbreaking down OHthis polymer?
  112. 112. The answer is D. This is a sucrose molecule,formed from glucose and fructose in acondensation reaction. The products of thisreaction are the sucrose molecule and water. Ifwater is added to sucrose, hydrolysis occurs andbreaks the covalent bonds between the subunits.
  113. 113. Photo Credits• Aaron Haupt• Corbis• Digital Stock• Elaine Shay• Mark Thayer• PhotoDisc• Alton Biggs
  114. 114. To advance to the next item or next page click on any of thefollowing keys: mouse, space bar, enter, down or forwardarrow. Click on this icon to return to the table of contents Click on this icon to return to the previous slide Click on this icon to move to the next slide Click on this icon to open the resources file.
  115. 115. End of Chapter 6 Show