February 5 AP Biology - John D. O'Bryant School of Math & Science
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AP Biology John D. O’Bryant School of Mathematics and Science February 5, 2013 AP Biology Do Now What is a virus? What makes a virus function? AP Biology Agenda Do Now (Quiz) Review: Biochemistry, Cellular Respiration, Photosynthesis Genetics of Viruses AP Biology Table of Contents (Notes/Classwork) Date Topic 1/29/13 What Darwin Never Knew 2/4/13 Review: Biochemistry, Cellular Respiration, Photosynthesis; Animal Behavior 2/5/13 Review: Biochemistry, Cellular Respiration, Photosynthesis; Animal Behavior; Genetics of Viruses Page number AP Bio Exam Review: Biochemistry & Cells Elements of Life • 25 elements • 96% : C, O, H, N • ~ 4% : P, S, Ca, K & trace elements (ex: Fe, I) Hint: Remember CHNOPS II. Atomic Structure • Atom = smallest unit of matter that retains properties of an element • Subatomic particles: Mass Location Charge (dalton or AMU) neutron 1 nucleus 0 proton 1 nucleus +1 electron negligible shell -1 Bonds Covalent Ionic Hydrogen All important to life Form cell’s molecules Quick reactions/ responses H bonds to other electronegative atoms Strong bond Weaker bond (esp. in H2O) Even weaker Made and broken by chemical reactions Weaker Bonds: Van der Waals Interactions: slight, fleeting attractions between atoms and molecules close together – Weakest bond – Eg. gecko toe hairs + wall surface 1. Polarity of H2O • O- will bond with H+ on a different molecule of H2O = hydrogen bond • H2O can form up to 4 bonds H2O Property Chemical Explanation Examples of Benefits to Life Cohesion •polar •H-bond •like-like ↑gravity plants, trees transpiration Adhesion •H-bond •unlike-unlike plants xylem bloodveins Surface Tension •diff. in stretch •break surface •H-bond bugswater Specific Heat •Absorbs & retains E •H-bond oceanmoderates temps protect marine life (under ice) Evaporation •liquidgas •KE Cooling Homeostasis •Polarityionic Good dissolver Universal Substance 4. Solvent of life • “like dissolves like” Hydrophilic Hydrophobic Affinity for H2O Appears to repel Polar, ions Nonpolar Cellulose, sugar, salt Oils, lipids Blood Cell membrane Acids and Bases Acid: adds H+ (protons); pH<7 Bases: removes protons, adds OH-; pH>7 Buffers = substances which minimize changes in concentration of H+ and OH- in a solution (weak acids and bases) • Buffers keep blood at pH ~7.4 • Good buffer = bicarbonate Figure 3.9 The pH of some aqueous solutions Functional Groups Functional Group Molecular Formula Names & Characteristics Draw an Example Hydroxyl -OH Alcohols Ethanol Carbonyl >CO Ketones (inside skeleton) Aldehydes (at end) Acetone Propanol Carboxyl -COOH Carboxylic acids (organic acids) Acetic acid Amino -NH2 Amines Glycine Sulfhydryl -SH Thiols Ethanethiol Phosphate -OPO32- / -OPO3H2 Organic phosphates Glycerol phosphate Monomers •Small organic •Used for building blocks of polymers •Connects with condensation reaction (dehydration synthesis) Polymers Macromolecules •Long molecules of •Giant molecules monomers •2 or more polymers •With many identical bonded together or similar blocks linked by covalent bonds ie. amino acid peptide polypeptide protein smaller larger Dehydration Synthesis (Condensation Reaction) Hydrolysis Make polymers Breakdown polymers Monomers Polymers Polymers Monomers A + B AB AB A + B + + H2O + H2O + I. Carbohydrates • Fuel and building • Sugars are the smallest carbs Provide fuel and carbon • monosaccharide disaccharide polysaccharide • Monosaccharides: simple sugars (ie. glucose) • Polysaccharides: Differ in Storage (plants-starch, animals-glycogen) Structure (plant-cellulose, arthropod-chitin) position & orientation of glycosidic linkage II. Lipids A.Fats: store large amounts of energy – saturated, unsaturated, polyunsaturated B.Steroids: cholesterol and hormones C.Phospholipids: cell membrane – hydrophilic head, hydrophobic tail – creates bilayer between cell and external environment Hydrophilic head Hydrophobic tail Four Levels of Protein Structure: 1. Primary – Amino acid sequence – 20 different amino acids – peptide bonds 2. Secondary – Gains 3-D shape (folds, coils) by H-bonding – α helix, β pleated sheet 3. Tertiary – Bonding between side chains (R groups) of amino acids – H & ionic bonds, disulfide bridges 4. Quaternary – 2+ polypeptides bond together amino acids polypeptides protein • Protein structure and function are sensitive to chemical and physical conditions • Unfolds or denatures if pH and temperature are not optimal IV. Nucleic Acids Nucleic Acids = Information Monomer: nucleotide DNA •Double helix •Thymine •Carries genetic code •Longer/larger •Sugar = deoxyribose RNA •Single strand •Uracil •Messenger (copies), translator •tRNA, rRNA, mRNA, RNAi •Work to make protein •Sugar = ribose Comparisons of Scopes Light Electron • Visible light passes through specimen • Light refracts light so specimen is magnified • Magnify up to 1000X • Specimen can be alive/moving • color • Focuses a beam of electrons through specimen • Magnify up to 1,000,000 times • Specimen non-living and in vacuum • Black and white Prokaryote Vs. Eukaryote • • • • • “before” “kernel” No nucleus DNA in a nucleoid Cytosol No organelles other than ribosomes • Small size • Primitive • i.e. bacteria • “true” “kernel” • Has nucleus and nuclear membrane • Cytosol • Has organelles with specialized structure and function • Much larger in size • More complex • i.e. plant/animal cell Parts of plant & animal cell p 108-109 • Cells must remain small to maintain a large surface area to volume ratio • Large S.A. allows increased rates of chemical exchange between cell and environment Animal cells have intercellular junctions: • Tight junction = prevent leakage • Desomosome = anchor cells together • Gap junction = allow passage of material Cell Membrane 6 types of membrane proteins Passive vs. Active Transport • Little or no Energy • Moves from high to low concentrations • Moves down the concentration gradient • i.e. diffusion, osmosis, facilitated diffusion (with a transport protein) • Requires Energy (ATP) • Moves from a low concentration to high • Moves against the concentration gradient • i.e. pumps, exo/endocytosis hypotonic / isotonic / hypertonic Exocytosis and Endocytosis transport large molecules 3 Types of Endocytosis: • Phagocytosis (“cell eating” solids) • Pinocytosis (“cell drinking” fluids) • Receptor-mediated endocytosis • Very specific • Substances bind to receptors on cell surface End 2/4/13 Concept 1: Analyzing the Processes of Cellular Respiration. Refer to pg 75-80 in Holtzclaw, Ch 9 in Campbell and media resources Refer to pg 326-328 in Holtzclaw, Lab 5 in LabBench Are these statements true or false? 1. Photosynthesis is the plant’s form of cellular respiration. 2. Plants respire only when they don’t photosynthesize. 3. Cellular respiration takes place only in plant roots, not throughout the plant. ALL OF THESE ARE FALSE! 1. Photosynthesis is the plant’s form of cellular respiration. FALSE 2. Plants respire only when they don’t photosynthesize. FALSE 3. Cellular respiration takes place only in plant roots, not throughout the plant. FALSE How is cellular metabolism relevant to higher levels of biological organization: physiology (breathing, digestion), ecology (communities)? How is cellular metabolism relevant to higher levels of biological organization: physiology (breathing, digestion), ecology (communities)? Cellular Respiration Catabolic ▪ Breaks down complex molecules into smaller ones Exergonic ▪ Releases energy that can be used to do work (such as build ATP from ADP and Pi) Cellular Respiration If you released all of the energy in sugar at once, what would happen? ▪ Quick combustion! FIRE ▪ Example: Marshmellows on Fire Cellular Respiration Instead, your mitochondria use a series of controlled steps, releasing energy in small amounts at a time ▪ Some energy still lost as heat ▪ The rest is converted to chemical energy in ATP for use in the cell! ▪ HOW????? Redox Reactions! Follows the movement of ELECTRONS from one chemical to another “X” is losing electrons “Y” is gaining electrons Redox Reactions! Lose Electrons, Oxidize Gain Electrons, Reduce Redox Reactions! Classic Chemistry Example… Redox Reactions! Cellular Respiration… Do you have any ideas as to how you can harness the movement of electrons to split up cellular respiration into steps?? Introducing…NAD+, a coenzyme electron carrier NAD+ + 2e - + H + produces NADH Is NAD+ reduced or oxidized? Introducing…NAD+, a coenzyme electron carrier NAD+ + 2e - + H + produces NADH Gain Electrons Reduce Also…FAD, a coenzyme electron carrier FAD + 2e - + 2H + produces FADH2 Gain Electrons Reduce Cellular respiration has three stages: 1. Glycolysis (breaks down glucose into two molecules of pyruvate) 2. The citric acid cycle (completes the breakdown of glucose) 3. Oxidative phosphorylation (accounts for most of the ATP synthesis) C6H12O6 + 6 O2 6 CO2 + 6 H2O + Energy (ATP + heat) Where can you find all of these reactants/products? To Prepare… Finish Comparison Chart Try Animations and Bioflix! Think of Project Ideas… The role of glycolysis in oxidizing glucose to two molecules of pyruvate The process that brings pyruvate from the cytosol into the mitochondria and introduces it into the citric acid cycle How the process of chemiosmosis utilizes the electrons from NADH and FADH2 to produce ATP The difference between fermentation and cellular respiration Concept 2: Analyzing the Processes of Photosynthesis Refer to pg 81-90 in Holtzclaw, Ch 10 in Campbell and media resources Refer to pg 321-323 in Holtzclaw, Lab 4 in LabBench Try This! Where does the biomass of a tree primarily come from? A. Oxygen B. Water C. Carbon dioxide D. Light E. Fertilizer Try This! Where does the biomass of a tree primarily come from? A. Oxygen B. Water C. Carbon dioxide D. Light E. Fertilizer Try This! An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is: a. Water from the soil b. Minerals from the soil c. CO2 from the air Try This! An acorn grows into an oak tree. The main source of the additional mass present in the oak tree is: a. Water from the soil b. Minerals from the soil c. CO2 from the air Chapter 10 You must know: How photosystems convert solar energy to chemical energy How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2 How chemiosmosis generates ATP in the light reactions How the Calvin cycle uses the energy molecules of the light reactions to produce G3P The metabolic adaptations of C4 and CAM plants to arid, dry regions AP Lab 4 You must know: The equation for photosynthesis and understand the process of photosynthesis The principles of chromatography and how to calculate Rf values The relationship between light wavelength or intensity and photosynthetic rate How to determine the rate of photosynthesis and then be able to design a controlled experiment to test the effect of some variable factor on photosynthesis Photosynthesis – The Basics CO2 + H2O → C6H12O6 + O2 1)Light Reactions “photo” 2)Calvin Cycle “synthesis” The Light Reactions Light energy excites electrons in chlorophyll Removal of electrons from H2O Formation of O2 Electron Transport Chain Reduction of NADP+ to NADPH Proton Motive Force ATP Synthase to produce ATP Try This Unlike in cellular respiration, the proton motive force generated by the light reactions in photosynthesis happens in three ways… Can you remember the three ways? 1. Electron transport chain powering the active transport of H+ into the thylakoid space 2. H+ produced in the thylakoid space from the splitting and oxidation of water 3. Removal of H+ from stroma during the reduction of NADP + to NADPH The Light Reactions Light energy excites electrons in chlorophyll Removal of electrons from H2O Formation of O2 (leaves stomata as a gas) Electron Transport Chain Reduction of NADP+ to NADPH Proton Motive Force ATP Synthase to produce ATP The Light Reactions The whole point was to transfer light energy to chemical energy in the form of: electrons in NADPH ATP Why? To power carbon fixation in the Calvin Cycle… The Calvin Cycle CO2 enters as a gas through the stomata (openings) of the leaves Through the power of NADPH and ATP, CO2 gets converted into an organic compound: a 3-carbon sugar called glyceraldehyde-3-phosphate (G3P) Can be converted to glucose, sucrose, starch, etc… Try This! Which experiment will produce 18O2? A. Exp 1 B. Exp 2 C. Both! D. Neither! Try This! Which experiment will produce 18O2? A. Exp 1 B. Exp 2 C. Both! D. Neither! Watch Bioflix! Chapter 10 You must know: How photosystems convert solar energy to chemical energy How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2 How chemiosmosis generates ATP in the light reactions How the Calvin cycle uses the energy molecules of the light reactions to produce G3P The metabolic adaptations of C4 and CAM plants to arid, dry regions Next Class… Adaptations to hot, arid climates… CAM plants and C4 plants Now… Practice Try #12 – 15, 17-19, 21-22 p. 91-92 Go over Comparison Charts Try animation activities (Campbell Online) Read about CAM plants and C4 plants P. 88-89 Holtzclaw P. 200-202 Campbell Activity: Photosynthesis in Dry Climates (Campbell Online) Concept 2: Analyzing the Processes of Photosynthesis PART 2 – Adaptations to Dry Climates Refer to pg 81-90 in Holtzclaw, Ch 10 in Campbell and media resources Refer to pg 321-323 in Holtzclaw, Lab 4 in LabBench Try This! Where does the organic biomass of a tree primarily come from? A. Oxygen B. Water C. Carbon dioxide D. Light E. Fertilizer Try This! Where does the organic biomass of a tree primarily come from? A. Oxygen B. Water C. Carbon dioxide D. Light E. Fertilizer Chapter 10 You must know: How photosystems convert solar energy to chemical energy How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2 How chemiosmosis generates ATP in the light reactions How the Calvin cycle uses the energy molecules of the light reactions to produce G3P The metabolic adaptations of C4 and CAM plants to arid, dry regions AP Lab 4 You must know: The equation for photosynthesis and understand the process of photosynthesis The principles of chromatography and how to calculate Rf values The relationship between light wavelength or intensity and photosynthetic rate How to determine the rate of photosynthesis and then be able to design a controlled experiment to test the effect of some variable factor on photosynthesis Photosynthesis – The Basics CO2 + H2O → C6H12O6 + O2 1)Light Reactions “photo” 2)Calvin Cycle “synthesis” The Light Reactions The Light Reactions Light energy excites electrons in chlorophyll Removal of electrons from H2O Formation of O2 Electron Transport Chain Reduction of NADP+ to NADPH Proton Motive Force ATP Synthase to produce ATP Try This Unlike in cellular respiration, the proton motive force generated by the light reactions in photosynthesis happens in three ways… Can you remember the three ways? 1. Electron transport chain powering the active transport of H+ into the thylakoid space 2. H+ produced in the thylakoid space from the splitting and oxidation of water 3. Removal of H+ from stroma during the reduction of NADP + to NADPH The Light Reactions The whole point was to transfer light energy to chemical energy in the form of: electrons in NADPH ATP Why? To power carbon fixation in the Calvin Cycle… The Calvin Cycle CO2 enters as a gas through the stomata (openings) of the leaves Through the power of NADPH and ATP, CO2 gets converted into an organic compound: a 3-carbon sugar called glyceraldehyde-3-phosphate (G3P) Can be converted to glucose, sucrose, starch, etc… Chapter 10 You must know: How photosystems convert solar energy to chemical energy How linear electron flow in the light reactions results in the formation of ATP, NADPH, and O2 How chemiosmosis generates ATP in the light reactions How the Calvin cycle uses the energy molecules of the light reactions to produce G3P The metabolic adaptations of C4 and CAM plants to arid, dry regions NOW… Adaptations to hot, arid climates… CAM plants and C4 plants Pineapple – CAM plant Sugarcane – C4 plant Hot, Dry Climates What’s the big deal? Stomata – water loss Rubisco – photorespiration Stomata… Stomata… Water exits via stomata during transpiration (evaporation of water through the stomata - which pulls water up the plant from the roots) If it’s a hot, dry day, plants need to minimize water loss! Solution? Close/minimize stomata BUT? Lowers CO2 intake… Rubisco… Remember rubisco? It’s the enzyme that fixes CO2 in the Calvin cycle of C3 plants The thing is… rubisco will also bind O2 in absence of CO2 Causes breakdown of Calvin Cycle products… Photorespiration Solution? Adapt! Try This! The presence of only Photosystem I, not Photosystem II, in the bundle sheath cells of C4 plants has an effect on O2 concentration. What is that effect, and how might that benefit the plant? Try This! The presence of only Photosystem I, not Photosystem II, in the bundle sheath cells of C4 plants has an effect on O2 concentration. What is that effect, and how might that benefit the plant? Without PS II, no O2 is generated in the bundle-sheath cells! This avoids the problem of O2 competing with CO2 for binding to rubisco No photorespiration Now… Practice Try #12 – 15, 17-19, 21-22 p. 91-92 Go over Comparison Charts Try animation activities (Campbell Online) Re-Read about CAM plants and C4 plants and do worksheet P. 88-89 Holtzclaw P. 200-202 Campbell Activity: Photosynthesis in Dry Climates (Campbell Online) Get Ready for Lab 4 Go through Lab 4 LabBench Checkpoint Next Class on Photosynthesis (Concept 2)
