Chapter 1 Introductory course Biology Camp
- 1. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings PowerPoint® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Introduction: Themes in the Study of Life Chapter 1
- 2. Evolution, the Overarching Theme of Biology • Evolution: change over time • Biology: study of life • Organisms living on Earth are modified descendants of common ancestors. – Evolutionary Adaptation – Response to the environment – Reproduction – Growth and Development – Energy Processes – Regulation – Order Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 3. Theme: New properties emerge at each level in the biological hierarchy • Life can be studied at different levels from molecules to the entire living planet. • The study of life can be divided into different levels of biological organization. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings • Biosphere • Ecosystem • Communities • Population • Organism • Organ & Organ Systems • Tissues • Cells • Organelles • Molecules • Atoms
- 4. Emergent Properties • Emergent properties: arrangement and interaction of parts within a system. • Reductionism: is the reduction of complex systems to simpler components that are more manageable to study. DNA • Systems biology constructs models for the dynamic behavior of whole biological systems. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 5. Theme: Organisms interact with their environments, exchanging matter and energy • Ecosystem Dynamics – Cycling of nutrients, in which materials acquired by plants eventually return to the soil. – Flow of energy from sunlight to producers to consumers. • energy transformations: energy exchange between an organism and its environment – enters as light and exiting as heat. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 6. Nutrient cycling and energy flow in an ecosystem Sunlight Ecosystem Heat Heat Cycling of chemical nutrients Producers (plants and other photosynthetic organisms) Chemical energy Consumers (such as animals)
- 7. Theme: Structure and Function are correlated at all levels of biological organization – For example, a leaf is thin and flat, maximizing the capture of light by chloroplasts. • Cell Theory: cells are the basic units of life – lowest level of organization that can perform all activities required for life. – enclosed by a membrane – DNA: genetic information • The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 8. (a) Wings (c) Neurons (b) Bones Infoldings of membrane Mitochondrion (d) Mitochondria 0.5 µm 100 µm Form fits function in a gull’s wing
- 9. • Eukaryotic cell: – membrane-enclosed organelles, – the largest of which is usually the nucleus – Plants, Animals, Fungi • Prokaryotic cell: – simpler and usually smaller – does not contain organelles, like a nucleus – Bacteria and Archae Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 10. 1 µm Organelles Nucleus (contains DNA) Cytoplasm Membrane DNA (no nucleus) Membrane Eukaryotic cell Prokaryotic cell
- 11. Theme: The continuity of life is based on heritable information in the form of DNA • Central Dogma: DNA --> RNA --> protein • Genes: units of inheritance from parents – DNA (deoxyribonucleic acid) • two long chains arranged in a double helix • Monomer: Nucleotide – instructions for proteins development & maintenance of organisms • Chromosomes: groups of genes • Genome: entire set of genetic instructions. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 12. Nuclei containing DNA Sperm cell Egg cell Fertilized egg with DNA from both parents Embryo’s cells with copies of inherited DNA Offspring with traits inherited from both parents Inherited DNA directs development of an organism
- 13. DNA: The genetic material Nucleus DNA Cell Nucleotide (a) DNA double helix (b) Single strand of DNA
- 14. Systems Biology at the Levels of Cells and Molecules • The human genome other organisms have been sequenced – Bioinformatics = the use of computational tools to process a large volume of data. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 15. Theme: Feedback mechanisms regulate biological systems • Negative feedback: more product present slows and lessens product production • Positive feedback: more product present speed up product production Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 16. Regulation by Feedback Mechanisms Negative feedback Excess D blocks a step D D D A B C Enzyme 1 Enzyme 2 Enzyme 3 D (a) Negative feedback W Enzyme 4 X Positive feedback Enzyme 5 Y + Enzyme 6 Excess Z stimulates a step Z Z Z Z (b) Positive feedback
- 17. The Core Theme: Evolution accounts for the unity and diversity of life • Organizing the Diversity of Life – ~1.8 million species have been identified – ~ total number of species: 10 million to over 100 million • Taxonomy: names and classifies species into groups Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 18. Classifying life Species Genus Family Order Class Phylum Kingdom Domain Ursus americanus (American black bear) Ursus Ursidae Carnivora Mammalia Chordata Animalia Eukarya
- 19. The Three Domains of Life • Domain Bacteria and Domain Archaea: prokaryotes. (No nucleus) • Domain Eukarya: eukaryotes. (Nucleus) – Plantae – Fungi – Animalia – Protista • DNA: universal genetic language Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 20. The three domains of life (a) DOMAIN BACTERIA (b) DOMAIN ARCHAEA (c) DOMAIN EUKARYA Protists Kingdom Fungi Kingdom Plantae Kingdom Animalia
- 21. (c) DOMAIN EUKARYA Protists Kingdom Fungi Kingdom Plantae Kingdom Animalia
- 22. An example of unity underlying the diversity of life: the architecture of cilia in eukaryotes Cilia of Paramecium Cross section of a cilium, as viewed with an electron microscope Cilia of windpipe cells 15 µm 5 µm 0.1 µm
- 23. Charles Darwin and the Theory of Natural Selection • Fossils and other evidence document the evolution of life on Earth over billions of years. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 24. • Charles Darwin (1859) On the Origin of Species by Means of Natural Selection – descent with modification & natural selection • duality of unity and diversity • Darwin observed that: – Individuals in a population have traits that vary. – Many of these traits are heritable – More offspring are produced than survive. – Competition is inevitable. – Species generally suit their environment. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 25. • Darwin inferred that: – Individuals that are best suited to their environment are more likely to survive and reproduce. – Over time, more individuals in a population will have the advantageous traits. • Natural Selection: natural environment “selects” for beneficial traits – adaptations of organisms to their way of life and environment. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 26. Natural Selection Population with varied inherited traits. Elimination of individuals with certain traits. Reproduction of survivors. Increasing frequency of traits that enhance survival and reproductive success. 4 3 2 1
- 28. The Tree of Life • descent with modification – Homologous structure: common skeletal architecture • forelimb of the bat, human, horse and the whale flipper – adaptive radiation: natural selection could cause an ancestral species to give rise to two or more descendent species • Galápagos Islands Finches. • phylogenetic trees : Evolutionary relationships are often illustrated with tree-like diagrams that show ancestors and their descendants Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 30. Inquiry is the search for information and explanation discovery science – natural structures and processes. – observation and the analysis of data. • Data recorded observations or information. – Qualitative: descriptions – Quantitative: measurements (tables & graphs) • Inductive reasoning: draws conclusions through logic – For example, “the sun always rises in the east.” Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 32. Hypothesis-Based Science • Observations: ask questions and propose hypotheses. – Hypothesis: tentative answer – Predictions: tested by observation or experimentation. • Deductive reasoning: general premises to make specific predictions – For example, if organisms are made of cells (premise 1), and humans are organisms (premise 2), then humans are composed of cells (deductive prediction). Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 33. A campground example of hypothesis- based inquiry Observations Question Hypothesis #1: Dead batteries Hypothesis #2: Burnt-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test prediction Test falsifies hypothesis Test does not falsify hypothesis
- 34. A Closer Look at Hypotheses in Scientific Inquiry • A hypothesis must be testable and falsifiable. • Hypothesis-based science often makes use of two or more alternative hypotheses. • Failure to falsify a hypothesis does not prove that hypothesis. – replace flashlight bulb now works • supports hypothesis of burnt bulb, but perhaps the first bulb was inserted incorrectly Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 35. Limitations of Science • In science, observations and experimental results must be repeatable. • Science cannot support or falsify supernatural explanations, which are outside the bounds of science. • In the context of science, a theory is: – Broader than a hypothesis – General, lead to new testable hypotheses – Supported by a large body of evidence than a hypothesis. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
- 36. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings PowerPoint® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Chapter 2 The Chemical Context of Life
- 37. • Organisms are composed of matter. • space and mass • made up of elements. • Element: cannot be broken down to other substances by chemical reactions. • Compound: two or more elements in a fixed ratio. – characteristics different from those of its elements. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 38. The emergent properties of a compound Sodium Chlorine Sodium chloride
- 39. Essential Elements of Life: C H O N • About 25 of the 92 elements are essential to life. • Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter. • Most of the remaining 4% consists of calcium, phosphorus, potassium, and sulfur. • Trace elements are those required by an organism in minute quantities. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 40. (a) Nitrogen deficiency (b) Iodine deficiency The effects of essential-element deficiencies
- 41. An element’s properties depend on the structure of its atoms • Atom: smallest unit of matter & retains the properties of an element. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings Subatomic Particles • Neutrons (0) and Protons (+) • atomic nucleus • Mass of Atom, measured in daltons • Electrons (-) • cloud around the nucleus
- 42. Cloud of negative charge (2 electrons) Simplified models of a helium (He) atom Nucleus Electrons (b) (a)
- 43. Atomic Number, Atomic Mass, Isotopes • atomic number = # protons • mass number = p + n • Atomic mass, the atom’s total mass, can be approximated by the mass number. • Isotopes are two atoms of an element that differ in number of neutrons. • Radioactive isotopes decay spontaneously, giving off particles and energy. – in biological research as tracers, in medical diagnosis and fossil dating. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 45. The Energy Levels of Electrons • Energy is the capacity to cause change. • Potential energy: location or structure. • electrons vary in potential energy • energy level or electron shell. • Orbital: 3-D space where an electron is 90% of the time. • Valence electrons: e- in the outermost shell, or valence shell – chemical behavior – full valence shell elements are chemically inert Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 46. Energy levels of an atom’s electrons (a) A ball bouncing down a flight of stairs provides an analogy for energy levels of electrons Third shell (highest energy level) Second shell (higher energy level) Energy absorbed First shell (lowest energy level) Atomic nucleus (b) Energy lost
- 47. Electron-distribution diagrams for the first 18 elements in the periodic table Hydrogen 1H Lithium 3Li Beryllium 4Be Boron 5B Carbon 6C Nitrogen 7N Oxygen 8O Fluorine 9F Neon 10Ne Helium 2He Atomic number Element symbol Electron- distribution diagram Atomic mass 2 He 4.00 First shell Second shell Third shell Sodium 11Na Magnesium 12Mg Aluminum 13Al Silicon 14Si Phosphorus 15P Sulfur 16S Chlorine 17Cl Argon 18Ar
- 48. The formation and function of molecules depend on chemical bonding between atoms • Chemical Bonds: atoms with incomplete valence shells can share or transfer valence • Covalent Bonds - Share pairs of electrons; molecule • Single bond: one pair of electrons. • Double bond: two pairs of electrons. • structural formula: H–H • molecular formula: H2 Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 49. Formation of covalent bond Hydrogen atoms (2 H) Hydrogen molecule (H2)
- 50. Covalent bonding in Water Molecules Water (H2O) Name and Molecular Formula Electron- distribution Diagram Lewis Dot Structure and Structural Formula Space- filling Model
- 51. • Electronegativity: atom’s attraction for the electrons – nonpolar covalent bond: electron equally shared – polar covalent bond: one atom is more electronegative • Unequal sharing of electrons causes a partial positive or negative charge Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 52. Ionic Bonds: Transfer electrons • Ion: a charged atom – Cation: + ion – Anion: - ion • ionic bond: attraction between an anion and a cation. – Salts – sodium chloride (table salt): in nature as crystals. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 53. Electron transfer and ionic bonding Na Cl Na Cl Na Sodium atom Chlorine atom Cl Na+ Sodium ion (a cation) Cl– Chloride ion (an anion) Sodium chloride (NaCl)
- 54. A sodium chloride crystal Na+ Cl–
- 55. Weak Chemical Bonds • reinforce shapes of large molecules and help molecules adhere to each other • hydrogen bond: hydrogen atom in a molecule is attracted another electronegative atom; N & O • Van der Waals Interactions – electrons are distributed asymmetrically in molecules, results positive or negative charge – attractions between molecules that are close together as a result of these charges. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 56. Hydrogen bond + + + + + Water (H2O) Ammonia (NH3) Hydrogen bond
- 58. Molecular Shape and Function • shape is determined by the positions of its atoms’ valence orbitals. • Biological molecules recognize and interact with each other with a specificity based on molecular shape. • Molecules with similar shapes can have similar biological effects Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 59. A Molecular Mimic (a) Structures of endorphin and morphine (b) Binding to endorphin receptors Natural endorphin Endorphin receptors Morphine Brain cell Morphine Natural endorphin Key Carbon Hydrogen Nitrogen Sulfur Oxygen
- 60. Chemical reactions make and break chemical bonds • Reactants Products • Photosynthesis: 6 CO2 + 6 H20 C6H12O6 + 6 O2 • completion: all reactants are converted to products. • Reversible reaction: products of the forward reaction become reactants for the reverse reaction. • Chemical equilibrium: forward and reverse reaction rates are equal. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
- 61. CHEMICAL REACTION = BONDS BREAK / ATOMS REARRANGE / NEW BONDS FORM Reactants Reaction Products 2 H2 O2 2 H2O
- 62. Photosynthesis: a solar-powered rearrangement of matter
- 63. You should now be able to: 1. unifying themes that characterize the biological sciences. 2. three domains of life, and the eukaryotic kingdoms. 3. discovery science and hypothesis-based science, quantitative and qualitative data, inductive and deductive reasoning, science and technology. 4. Identify the four major elements. 5. neutron and proton, atomic number and mass number, atomic weight and mass number. 6. nonpolar covalent bonds, polar covalent bonds, ionic bonds, hydrogen bonds, and van der Waals interactions. Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Editor's Notes
- #6: Figure 1.5
- #8: Figure 1.6
- #10: Figure 1.8 Contrasting eukaryotic and prokaryotic cells in size and complexity
- #12: Figure 1.9
- #13: Figure 1.10
- #16: Figure 1.13
- #18: Figure 1.14
- #20: Figure 1.15
- #21: Figure 1.15 The three domains of life
- #22: Figure 1.16
- #26: Figure 1.20
- #27: Figure 1.21
- #31: Figure 1.23
- #33: Figure 1.24
- #38: Figure 2.3 The emergent properties of a compound
- #40: Figure 2.4 The effects of essential-element deficiencies
- #42: Figure 2.5 Simplified models of a helium (He) atom
- #44: Figure 2.7 A PET scan, a medical use for radioactive isotopes
- #46: Figure 2.8 Energy levels of an atom’s electrons
- #47: Figure 2.9 Electron-distribution diagrams for the first 18 elements in the periodic table
- #49: Figure 2.11 Formation of a covalent bond
- #50: Figure 2.12 Covalent bonding in four molecules
- #53: Figure 2.14 Electron transfer and ionic bonding
- #54: Figure 2.15 A sodium chloride crystal
- #56: Figure 2.16 A hydrogen bond
- #59: Figure 2.18 A molecular mimic
- #62: Figure 2.19 Photosynthesis: a solar-powered rearrangement of matter