Becker's World of the Cell

Cover
Title Page
Copyright
About The Authors
Detailed Contents
Preface
Acknowledgments
Chapter 1. A Preview of Cell Biology
	1.1 The Cell Theory: A Brief History
		Advances in Microscopy Allowed Detailed Studies of Cells
		The Cell Theory Applies to All Organisms
	1.2 The Emergence of Modern Cell Biology
		The Cytological Strand Deals with Cellular Structure
		The Biochemical Strand Concerns the Chemistry of Biological Structure and Function
		The Genetic Strand Focuses on Information Flow
	1.3 How Do We Know What We Know?
		Biological “Facts” May Turn Out to Be Incorrect
		Experiments Test Specific Hypotheses
		Model Organisms Play a Key Role in Modern Cell Biology Research
		Well-Designed Experiments Alter Only One Variable at a Time
	Summary of Key Points
	Problem Set
	Key Technique: Using Immunofluorescence to Identify Specific Cell Components
	Human Connections: The Immortal Cells of Henrietta Lacks
Chapter 2. The Chemistry of the Cell
	2.1 The Importance of Carbon
		Carbon-Containing Molecules Are Stable
		Carbon-Containing Molecules Are Diverse
		Carbon-Containing Molecules Can Form Stereoisomers
	2.2 The Importance of Water
		Water Molecules Are Polar
		Water Molecules Are Cohesive
		Water Has a High Temperature-Stabilizing Capacity
		Water Is an Excellent Solvent
	2.3 The Importance of Selectively Permeable Membranes
		A Membrane Is a Lipid Bilayer with Proteins Embedded in It
		Lipid Bilayers Are Selectively Permeable
	2.4 The Importance of Synthesis by Polymerization
		Macromolecules Are Critical for Cellular Form and Function
		Cells Contain Three Different Kinds of Macromolecular Polymers
		Macromolecules Are Synthesized by Stepwise Polymerization of Monomers
	2.5 The Importance of Self-Assembly
		Noncovalent Bonds and Interactions Are Important in the Folding of Macromolecules
		Many Proteins Spontaneously Fold into Their Biologically Functional State
		Molecular Chaperones Assist the Assembly of Some Proteins
		Self-Assembly Also Occurs in Other Cellular Structures
		The Tobacco Mosaic Virus Is a Case Study in Self-Assembly
		Self-Assembly Has Limits
		Hierarchical Assembly Provides Advantages for the Cell
	Summary of Key Points
	Problem Set
	Key Technique: Determining the Chemical Fingerprint of a Cell Using Mass Spectrometry
	Human Connections: Taking a Deeper Look: Magnetic Resonance Imaging (MRI)
Chapter 3. The Macromolecules of the Cell
	3.1 Proteins
		The Monomers Are Amino Acids
		The Polymers Are Polypeptides and Proteins
		Several Kinds of Bonds and Interactions Are Important in Protein Folding and Stability
		Protein Structure Depends on Amino Acid Sequence and Interactions
	3.2 Nucleic Acids
		The Monomers Are Nucleotides
		The Polymers Are DNA and RNA
		A DNA Molecule Is a Double-Stranded Helix
	3.3 Polysaccharides
		The Monomers Are Monosaccharides
		The Polymers Are Storage and Structural Polysaccharides
		Polysaccharide Structure Depends on the Kinds of Glycosidic Bonds Involved
	3.4 Lipids
		Fatty Acids Are the Building Blocks of Several Classes of Lipids
		Triacylglycerols Are Storage Lipids
		Phospholipids Are Important in Membrane Structure
		Glycolipids Are Specialized Membrane Components
		Steroids Are Lipids with a Variety of Functions
		Terpenes Are Formed from Isoprene
	Summary of Key Points
	Problem Set
	Human Connections: Aggregated Proteins and Alzheimer’s
	Key Technique: Using X-Ray Crystallography to Determine Protein Structure
Chapter 4. Cells and Organelles
	4.1 The Origins of the First Cells
		Simple Organic Molecules May Have Formed Abiotically in the Young Earth
		RNA May Have Been the First Informational Molecule
		Liposomes May Have Defined the First Primitive Protocells
	4.2 Basic Properties of Cells
		The Three Domains of Life Are Bacteria, Archaea, and Eukaryotes
		There Are Several Limitations on Cell Size
		Bacteria, Archaea, and Eukaryotes Differ from Each Other in Many Ways
	4.3 The Eukaryotic Cell in Overview: Structure and Function
		The Plasma Membrane Defines Cell Boundaries and Retains Contents
		The Nucleus Is the Information Center of the Eukaryotic Cell
		Mitochondria and Chloroplasts Provide Energy for the Cell
		The Endosymbiont Theory Proposes That Mitochondria and Chloroplasts Were Derived from Bacteria
		The Endomembrane System Synthesizes Proteins for a Variety of Cellular Destinations
		Other Organelles Also Have Specific Functions
		Ribosomes Synthesize Proteins in the Cytoplasm
		The Cytoskeleton Provides Structure to the Cytoplasm
		The Extracellular Matrix and Cell Walls Are Outside the Plasma Membrane
	4.4 Viruses, Viroids, and Prions: Agents That Invade Cells
		A Virus Consists of a DNA or RNA Core Surrounded by a Protein Coat
		Viroids Are Small, Circular RNA Molecules That Can Cause Plant Diseases
		Prions Are Infectious Protein Molecules
	Summary of Key Points
	Problem Set
	Human Connections: When Cellular “Breakdown” Breaks Down
	Key Technique: Using Centrifugation to Isolate Organelles
Chapter 5. Bioenergetics: The Flow of Energy in the Cell
	5.1 The Importance of Energy
		Cells Need Energy to Perform Six Different Kinds of Work
		Organisms Obtain Energy Either from Sunlight or from the Oxidation of Chemical Compounds
		Energy Flows Through the Biosphere Continuously
		The Flow of Energy Through the Biosphere Is Accompanied by a Flow of Matter
	5.2 Bioenergetics
		Understanding Energy Flow Requires Knowledge of Systems, Heat, and Work
		The First Law of Thermodynamics States That Energy Is Conserved
		The Second Law of Thermodynamics States That Reactions Have Directionality
		Entropy and Free Energy Are Two Means of Assessing Thermodynamic Spontaneity
	5.3 Understanding ΔG and Keq
		The Equilibrium Constant Keq Is a Measure of Directionality
		ΔG Can Be Calculated Readily
		The Standard Free Energy Change Is ΔG Measured Under Standard Conditions
		Summing Up: The Meaning of ΔGʹ and ΔG°ʹ
		Free Energy Change: Sample Calculations
		Jumping Beans Provide a Useful Analogy for Bioenergetics
		Life Requires Steady-State Reactions That Move Toward Equilibrium Without Ever Getting There
	Summary of Key Points
	Problem Set
	Human Connections: The “Potential” of Food to Provide Energy
	Key Technique: Measuring How Molecules Bind to One Another Using Isothermal Titration Calorimetry
Chapter 6. Enzymes: The Catalysts of Life
	6.1 Activation Energy and the Metastable State
		Before a Chemical Reaction Can Occur, the Activation Energy Barrier Must Be Overcome
		The Metastable State Is a Result of the Activation Barrier
		Catalysts Overcome the Activation Energy Barrier
	6.2 Enzymes as Biological Catalysts
		Most Enzymes Are Proteins
		Substrate Binding, Activation, and Catalysis Occur at the Active Site
		Ribozymes Are Catalytic RNA Molecules
	6.3 Enzyme Kinetics
		Monkeys and Peanuts Provide a Useful Analogy for Understanding Enzyme Kinetics
		Most Enzymes Display Michaelis–Menten Kinetics
		What Is the Meaning of V max and Km?
		Why Are Km and Vmax Important to Cell Biologists?
		The Double-Reciprocal Plot Is a Useful Means of Visualizing Kinetic Data
		Enzyme Inhibitors Act Either Irreversibly or Reversibly
	6.4 Enzyme Regulation
		Allosteric Enzymes Are Regulated by Molecules Other than Reactants and Products
		Allosteric Enzymes Exhibit Cooperative Interactions Between Subunits
		Enzymes Can Also Be Regulated by the Addition or Removal of Chemical Groups
	Summary of Key Points
	Problem Set
	Human Connections: Ace Inhibitors: Enzyme Activity as TheDifference Between Life and Death
	Key Technique: Determining Km and Vmax Using Enzyme Assays
Chapter 7. Membranes: Their Structure, Function, and Chemistry
	7.1 The Functions of Membranes
		Membranes Define Boundaries and Serve as Permeability Barriers
		Membranes Contain Specific Proteins and Therefore Have Specific Functions
		Membrane Proteins Regulate the Transport of Solutes
		Membrane Proteins Detect and Transmit Electrical and Chemical Signals
		Membrane Proteins Mediate Cell Adhesion and Cell-to-Cell Communication
	7.2 Models of Membrane Structure: An Experimental Perspective
		Overton and Langmuir: Lipids Are Important Components of Membranes
		Gorter and Grendel: The Basis of Membrane Structure Is a Lipid Bilayer
		Davson and Danielli: Membranes Also Contain Proteins
		Robertson: All Membranes Share a Common Underlying Structure
		Further Research Revealed Major Shortcomings of the Davson–Danielli Model
		Singer and Nicolson: A Membrane Consists of a Mosaic of Proteins in a Fluid Lipid Bilayer
		Unwin and Henderson: Most Membrane Proteins Contain Transmembrane Segments
	7.3 Membrane Lipids: The “Fluid” Part of the Model
		Membranes Contain Several Major Classes of Lipids
		Fatty Acids Are Essential to Membrane Structure and Function
		Thin-Layer Chromatography Is an Important Technique for Lipid Analysis
		Membrane Asymmetry: Most Lipids Are Distributed Unequally Between the Two Monolayers
		The Lipid Bilayer Is Fluid
		Most Organisms Can Regulate Membrane Fluidity
		Lipid Micro- or Nanodomains May Localize Molecules in Membranes
	7.4 Membrane Proteins: The “Mosaic” Part of the Model
		The Membrane Consists of a Mosaic of Proteins: Evidence from Freeze-Fracture Microscopy
		Membranes Contain Integral, Peripheral, and Lipid-Anchored Proteins
		Membrane Proteins Can Be Isolated and Analyzed
		Determining the Three-Dimensional Structure of Membrane Proteins Is Becoming Easier
		Molecular Biology Has Contributed Greatly to Our Understanding of Membrane Proteins
		Membrane Proteins Have a Variety of Functions
		Membrane Proteins Are Oriented Asymmetrically Across the Lipid Bilayer
		Many Membrane Proteins and Lipids Are Glycosylated
		Membrane Proteins Vary in Their Mobility
		The Erythrocyte Membrane Contains an Interconnected Network of Membrane-Associated Proteins
	Summary of Key Points
	Problem Set
	Key Technique: Fluorescence Recovery After Photobleaching (FRAP)
	Human Connections: It’s All in the Family
Chapter 8. Transport Across Membranes: Overcoming the Permeability Barrier
	8.1 Cells and Transport Processes
		Solutes Cross Membranes by Simple Diffusion, Facilitated Diffusion, and Active Transport
		The Movement of a Solute Across a Membrane Is Determined by Its Concentration Gradient or Its Electrochemical Potential
		The Erythrocyte Plasma Membrane Provides Examples of Transport
	8.2 Simple Diffusion: Unassisted Movement Down the Gradient
		Simple Diffusion Always Moves Solutes Toward Equilibrium
		Osmosis Is the Simple Diffusion of Water Across a Selectively Permeable Membrane
		Simple Diffusion Is Typically Limited to Small, Uncharged Molecules
		The Rate of Simple Diffusion Is Directly Proportional to the Concentration Gradient
	8.3 Facilitated Diffusion: Protein-Mediated Movement Down the Gradient
		Carrier Proteins and Channel Proteins Facilitate Diffusion by Different Mechanisms
		Carrier Proteins Alternate Between Two Conformational States
		Carrier Proteins Are Analogous to Enzymes in Their Specificity and Kinetics
		Carrier Proteins Transport Either One or Two Solutes
		The Erythrocyte Glucose Transporter and Anion Exchange Protein Are Examples of Carrier Proteins
		Channel Proteins Facilitate Diffusion by Forming Hydrophilic Transmembrane Channels
	8.4 Active Transport: Protein-Mediated Movement Up the Gradient
		The Coupling of Active Transport to an Energy Source May Be Direct or Indirect
		Direct Active Transport Depends on Four Types of Transport ATPases
		Indirect Active Transport Is Driven by Ion Gradients
	8.5 Examples of Active Transport
		Direct Active Transport: The Na+/K+ Pump Maintains Electrochemical Ion Gradients
		Indirect Active Transport: Sodium Symport Drives the Uptake of Glucose
		The Bacteriorhodopsin Proton Pump Uses Light Energy to Transport Protons
	8.6 The Energetics of Transport
		For Uncharged Solutes, the ΔG of Transport Depends Only on the Concentration Gradient
		For Charged Solutes, the ΔG of Transport Depends on the Electrochemical Potential
	Summary of Key Points
	Problem Set
	Key Technique: Expression of Heterologous Membrane Proteins in Frog Oocytes
	Human Connections: Membrane Transport, Cystic Fibrosis, and the Prospects for Gene Therapy
Chapter 9. Chemotrophic Energy Metabolism: Glycolysis and Fermentation
	9.1 Metabolic Pathways
	9.2 ATP: The Primary Energy Molecule in Cells
		ATP Contains Two Energy-Rich Phosphoanhydride Bonds
		ATP Hydrolysis Is Exergonic Due to Several Factors
		ATP Is Extremely Important in Cellular Energy Metabolism
	9.3 Chemotrophic Energy Metabolism
		Biological Oxidations Usually Involve the Removal of Both Electrons and Protons and Are Exergonic
		Coenzymes Such as NAD+ Serve as Electron Acceptors in Biological Oxidations
		Most Chemotrophs Meet Their Energy Needs by Oxidizing Organic Food Molecules
		Glucose Is One of the Most Important Oxidizable Substrates in Energy Metabolism
		The Oxidation of Glucose Is Highly Exergonic
		Glucose Catabolism Yields Much More Energy in the Presence of Oxygen Than in Its Absence
		Based on Their Need for Oxygen, Organisms Are Aerobic, Anaerobic, or Facultative
	9.4 Glycolysis: ATP Generation Without the Involvement of Oxygen
		Glycolysis Generates ATP by Catabolizing Glucose to Pyruvate
	9.5 Fermentation
		In the Absence of Oxygen, Pyruvate Undergoes Fermentation to Regenerate NAD+
		Fermentation Taps Only a Fraction of the Substrate’s Free Energy but Conserves That Energy Efficiently as ATP
		Cancer Cells Ferment Glucose to Lactate Even in the Presence of Oxygen
	9.6 Alternative Substrates for Glycolysis
		Other Sugars and Glycerol Are Also Catabolized by the Glycolytic Pathway
		Polysaccharides Are Cleaved to Form Sugar Phosphates That Also Enter the Glycolytic Pathway
	9.7 Gluconeogenesis
	9.8 The Regulation of Glycolysis and Gluconeogenesis
		Key Enzymes in the Glycolytic and Gluconeogenic Pathways Are Subject to Allosteric Regulation
		Fructose-2,6-Bisphosphate Is an Important Regulator of Glycolysis and Gluconeogenesis
		Glycolytic Enzymes May Have Functions Beyond Glycolysis
	Summary of Key Points
	Problem Set
	Key Technique: Using Isotopic Labeling to Determine the Fate of Atoms in a Metabolic Pathway
	Human Connections: What Happens to the Sugar?
Chapter 10. Chemotrophic Energy Metabolism: Aerobic Respiration
	10.1 Cellular Respiration: Maximizing ATP Yields
		Aerobic Respiration Yields Much More Energy than Fermentation Does
		Respiration Includes Glycolysis, Pyruvate Oxidation, the Citric Acid Cycle, Electron Transport, and ATP Synthesis
	10.2 The Mitochondrion: Where the Action Takes Place
		Mitochondria Are Often Present Where the ATP Needs Are Greatest
		Mitochondria Can Adopt Complex Shapes and Vary in Number in Different Cell Types
		The Outer and Inner Membranes Define Two Separate Mitochondrial Compartments and Three Regions
		Many Mitochondrial Proteins Originate in the Cytosol
		Mitochondrial Functions Occur in or on Specific Membranes and Compartments
		In Bacteria, Respiratory Functions Are Localized to the Plasma Membrane and the Cytoplasm
	10.3 The Citric Acid Cycle: Oxidation in the Round
		Pyruvate Is Converted to Acetyl Coenzyme A by Oxidative Decarboxylation
		The Citric Acid Cycle Begins with the Entry of Two Carbons from Acetyl CoA
		Two Oxidative Decarboxylations Then Form NADH and Release CO2
		Direct Generation of GTP (or ATP) Occurs at One Step in the Citric Acid Cycle
		The Final Oxidative Reactions of the Citric Acid Cycle Generate FADH2 and NADH
		Summing Up: The Products of the Citric Acid Cycle Are CO2 , ATP, NADH, and FADH2
		Several Citric Acid Cycle Enzymes Are Subject to Allosteric Regulation
		The Citric Acid Cycle Also Plays a Central Role in the Catabolism of Fats and Proteins
		The Citric Acid Cycle Serves as a Source of Precursors for Anabolic Pathways
		The Glyoxylate Cycle Converts Acetyl CoA to Carbohydrates in Plants
	10.4 Electron Transport: Electron Flow from Coenzymes to Oxygen
		The Electron Transport Chain Conveys Electrons from Reduced Coenzymes to Oxygen
		The Electron Transport Chain Consists of Five Kinds of Carriers
		The Electron Carriers Function in a Sequence Determined by Their Reduction Potentials
		Most of the Carriers Are Organized into Four Large Respiratory Complexes
		The Respiratory Complexes Move Freely Within the Inner Membrane
	10.5 The Electrochemical Proton Gradient: Key to Energy Coupling
		Electron Transport and ATP Synthesis Are Coupled Events
		Coenzyme Oxidation Pumps Enough Protons to Form Three ATP Moleculesper NADH and Two ATP Molecules per FADH2
		The Chemiosmotic Model Is Affirmed by an Impressive Array of Evidence
	10.6 ATP Synthesis: Putting It All Together
		F1 Particles Have ATP Synthase Activity
		Proton Translocation Through Fo Drives ATP Synthesis by F1
		ATP Synthesis by FoF1 Involves Physical Rotation of the Gamma Subunit
	10.7 Aerobic Respiration: Summing It All Up
		The Actual ATP Yield per Glucose during Aerobic Respiration Is Influencedby Several Factors
		Aerobic Respiration: A Remarkable Process
	Summary of Key Points
	Problem Set
	Key Technique: Visualizing Cellular Structures with Three-Dimensional Electron Microscopy
	Human Connections: A Diet Worth Dying For?
Chapter 11. Phototrophic Energy Metabolism: Photosynthesis
	11.1 An Overview of Photosynthesis
		The Energy Transduction Reactions Convert Solar Energy to Chemical Energy
		The Carbon Assimilation Reactions Fix Carbon by Reducing Carbon Dioxide
		The Chloroplast Is the Photosynthetic Organelle in Eukaryotic Cells
		Chloroplasts Are Composed of Three Membrane Systems
	11.2 Photosynthetic Energy Transduction I: Light Harvesting
		Chlorophyll Is Life’s Primary Link to Sunlight
		Accessory Pigments Further Expand Access to Solar Energy
		Light-Gathering Molecules Are Organized into Photosystems and Light-Harvesting Complexes
		Oxygenic Phototrophs Have Two Types of Photosystems
	11.3 Photosynthetic Energy Transduction II: NADPH Synthesis
		Photosystem II Transfers Electrons from Water to a Plastoquinone
		The Cytochrome b6/f Complex Transfers Electrons from a Plastoquinol to Plastocyanin
		Photosystem I Transfers Electrons from Plastocyanin to Ferredoxin
		Ferredoxin-NADP+ Reductase Catalyzes the Reduction of NADP+
	11.4 Photosynthetic Energy Transduction III: ATP Synthesis
		A Chloroplast ATP Synthase Couples Transport of Protons Across the Thylakoid Membrane to ATP Synthesis
		Cyclic Photophosphorylation Allows a Photosynthetic Cell to Balance NADPH and ATP Synthesis
		A Summary of the Complete Energy Transduction System
		Bacteria Use a Photosynthetic Reaction Center and Electron Transport System Similar to Those in Plants
	11.5 Photosynthetic Carbon Assimilation I: The Calvin Cycle
		Carbon Dioxide Enters the Calvin Cycle by Carboxylation of Ribulose-1,5-Bisphosphate
		3-Phosphoglycerate Is Reduced to Form Glyceraldehyde-3-Phosphate
		Regeneration of Ribulose-1,5-Bisphosphate Allows Continuous Carbon Assimilation
		The Complete Calvin Cycle and Its Relation to Photosynthetic Energy Transduction
	11.6 Regulation of the Calvin Cycle
		The Calvin Cycle Is Highly Regulated to Ensure Maximum Efficiency
		Rubisco Activase Regulates Carbon Fixation by Rubisco
	11.7 Photosynthetic Carbon Assimilation II: Carbohydrate Synthesis
		Glucose-1-Phosphate Is Synthesized from Triose Phosphates
		Biosynthesis of Sucrose Occurs in the Cytosol
		Biosynthesis of Starch Occurs in the Chloroplast Stroma
		Photosynthesis Also Produces Reduced Nitrogen and Sulfur Compounds
	11.8 Rubisco’s Oxygenase Activity Decreases Photosynthetic Efficiency
		The Glycolate Pathway Returns Reduced Carbon from Phosphoglycolate to the Calvin Cycle
		C4 Plants Minimize Photorespiration by Confining Rubisco to CellsContaining High Concentrations of CO2
		CAM Plants Minimize Photorespiration and Water Loss by Opening Their Stomata Only at Night
	Summary of Key Points
	Problem Set
	Key Technique: Determining Absorption and Action Spectra via Spectrophotometry
	Human Connections: How Do Plants Put On Sunscreen?
Chapter 12. The Endomembrane System and Protein Sorting
	12.1 The Endoplasmic Reticulum
		The Two Basic Kinds of Endoplasmic Reticulum Differ in Structure and Function
		Rough ER Is Involved in the Biosynthesis and Processing of Proteins
		Smooth ER Is Involved in Drug Detoxification, Carbohydrate Metabolism, Calcium Storage, and Steroid Biosynthesis
		The ER Plays a Central Role in the Biosynthesis of Membranes
	12.2 The Golgi Apparatus
		The Golgi Apparatus Consists of a Series of Membrane-Bounded Cisternae
		Two Models Account for the Flow of Lipids and Proteins Through the Golgi Apparatus
	12.3 Roles of the ER and Golgi Apparatus in Protein Processing
		Protein Folding and Quality Control Take Place Within the ER
		Initial Glycosylation Occurs in the ER
		Further Glycosylation Occurs in the Golgi Apparatus
	12.4 Roles of the ER and Golgi Apparatus In Protein Trafficking
		Cotranslational Import Allows Some Polypeptides to Enter the ER as They Are Being Synthesized
		The Signal Recognition Particle (SRP) Attaches the Ribosome-mRNA-PolypeptideComplex to the ER Membrane
		Proteins Released into the ER Lumen Are Routed to the Golgi Apparatus, Secretory Vesicles, Lysosomes, or Back to the ER
		Stop-Transfer Sequences Mediate the Insertion of Integral Membrane Proteins
		Posttranslational Import Is an Alternative Mechanism for Import into the ER Lumen
	12.5 Exocytosis and Endocytosis: Transporting Material Across the Plasma Membrane
		Secretory Pathways Transport Molecules to the Exterior of the Cell
		Exocytosis Releases Intracellular Molecules Outside the Cell
		Endocytosis Imports Extracellular Molecules by Forming Vesicles from the Plasma Membrane
	12.6 Coated Vesicles in Cellular Transport Processes
		Clathrin-Coated Vesicles Are Surrounded by Lattices Composed of Clathrin and Adaptor Protein
		The Assembly of Clathrin Coats Drives the Formation of Vesicles from the Plasma Membrane and TGN
		COPI- and COPII-Coated Vesicles Travel Between the ER and Golgi Apparatus Cisternae
		SNARE Proteins Mediate Fusion Between Vesicles and Target Membranes
	12.7 Lysosomes and Cellular Digestion
		Lysosomes Isolate Digestive Enzymes from the Rest of the Cell
		Lysosomes Develop from Endosomes
		Lysosomal Enzymes Are Important for Several Different Digestive Processes
		Lysosomal Storage Diseases Are Usually Characterized by the Accumulation of Indigestible Material
		The Plant Vacuole: A Multifunctional Digestive Organelle
	12.8 Peroxisomes
		Most Peroxisomal Functions Are Linked to Hydrogen Peroxide Metabolism
		Plant Cells Contain Types of Peroxisomes Not Found in Animal Cells
		Peroxisome Biogenesis Can Occur by Division of Preexisting Peroxisomes or by Vesicle Fusion
	Summary of Key Points
	Problem Set
	Key Technique: Visualizing Vesicles at the Cell Surface Using Total Internal Reflection (TIRF) Microscopy
	Human Connections: A Bad Case of the Munchies? (Autophagy In Inflammatory Bowel Disease)
Chapter 13. Cytoskeletal Systems
	13.1 Major Structural Elements of the Cytoskeleton
		Eukaryotes Have Three Basic Types of Cytoskeletal Elements
		Bacteria Have Cytoskeletal Systems That Are Structurally Similar to Those in Eukaryotes
		The Cytoskeleton Is Dynamically Assembled and Disassembled
	13.2 Microtubules
		Two Types of Microtubules Are Responsible for Many Functions in the Cell
		Tubulin Heterodimers Are the Protein Building Blocks of Microtubules
		Microtubules Can Form as Singlets, Doublets, or Triplets
		Microtubules Form by the Addition of Tubulin Dimers at Their Ends
		Addition of Tubulin Dimers Occurs More Quickly at the Plus Ends of Microtubules
		Drugs Can Affect the Assembly and Stability of Microtubules
		GTP Hydrolysis Contributes to the Dynamic Instability of Microtubules
		Microtubules Originate from Microtubule-Organizing Centers Within the Cell
		MTOCs Organize and Polarize Microtubules Within Cells
		Microtubule Stability Is Tightly Regulated in Cells by a Variety of Microtubule-Binding Proteins
	13.3 Microfilaments
		Actin Is the Protein Building Block of Microfilaments
		Different Types of Actin Are Found in Cells
		G-Actin Monomers Polymerize into F-Actin Microfilaments
		Specific Drugs Affect Polymerization of Microfilaments
		Cells Can Dynamically Assemble Actin into a Variety of Structures
		Actin-Binding Proteins Regulate the Polymerization, Length, and Organization of Microfilaments
		Proteins That Link Actin to Membranes
		Phospholipids and Rho Family GTPases Regulate Where and When Actin-Based Structures Assemble
	13.4 Intermediate Filaments
		Intermediate Filament Proteins Are Tissue Specific
		Intermediate Filaments Assemble from Fibrous Subunits
		Intermediate Filaments Confer Mechanical Strength on Tissues
		The Cytoskeleton Is a Mechanically Integrated Structure
	Summary of Key Points
	Problem Set
	Key Technique: Studying the Dynamic Cytoskeleton
	Human Connections: When Actin Kills
Chapter 14. Cellular Movement: Motility and Contractility
	14.1 Microtubule-Based Movement Inside Cells: Kinesins and Dyneins
		Motor Proteins Move Cargoes Along MTs During Axonal Transport
		Classic Kinesins Move Toward the Plus Ends of Microtubules
		Kinesins Are a Large Family of Proteins
		Dyneins Are Found in Axonemes and the Cytosol
		Microtubule Motors Direct Vesicle Transport and Shape the Endomem-brane System
	14.2 Microtubule-Based Cell Motility: Cilia And Flagella
		Cilia and Flagella Are Common Motile Appendages of Eukaryotic Cells
		Cilia and Flagella Consist of an Axoneme Connected to a Basal Body
		Doublet Sliding Within the Axoneme Causes Cilia and Flagella to Bend
	14.3 Microfilament-Based Movement Inside Cells: Myosins
		Myosins Are a Large Family of Actin-Based Motors with Diverse Roles in Cell Motility
		Many Myosins Move Along Actin Filaments in Short Steps
	14.4 Microfilament-Based Motility: Muscle Cells In Action
		Skeletal Muscle Cells Contain Thin and Thick Filaments
		Sarcomeres Contain Ordered Arrays of Actin, Myosin, and Accessory Proteins
		The Sliding-Filament Model Explains Muscle Contraction
		Cross-Bridges Hold Filaments Together, and ATP Powers Their Movement
		The Regulation of Muscle Contraction Depends on Calcium
		The Coordinated Contraction of Cardiac Muscle Cells Involves Electrical Coupling
		Smooth Muscle Is More Similar to Nonmuscle Cells than to Skeletal Muscle
	14.5 Microfilament-Based Motility In Nonmuscle Cells
		Cell Migration via Lamellipodia Involves Cycles of Protrusion, Attachment, Translocation, and Detachment
		Chemotaxis Is a Directional Movement in Response to a Graded Chemical Stimulus
		Amoeboid Movement Involves Cycles of Gelation and Solation of Actin
		Actin-Based Motors Move Components Within the Cytosol of Some Cells
	Summary of Key Points
	Problem Set
	Key Technique: Watching Motors Too Small to See
	Human Connections: Dyneins Help Us Tell Left From Right
Chapter 15. Beyond the Cell: Cell Adhesions, Cell Junctions, and Extracellular Structures
	15.1 Cell-Cell Junctions
		Adhesive Junctions Link Adjoining Cells
		Transient Cell-Cell Adhesions Are Important for Many Cellular Events
		Tight Junctions Prevent the Movement of Molecules Across Cell Layers
		Gap Junctions Allow Direct Electrical and Chemical Communication Between Cells
	15.2 The Extracellular Matrix of Animal Cells
		Collagens Are Responsible for the Strength of the Extracellular Matrix
		Elastins Impart Elasticity and Flexibility to the Extracellular Matrix
		Collagen and Elastin Fibers Are Embedded in a Matrix of Proteoglycans
		Free Hyaluronate Lubricates Joints and Facilitates Cell Migration
		Adhesive Glycoproteins Anchor Cells to the Extracellular Matrix
		Fibronectins Bind Cells to the ECM and Foster Cellular Movement
		Laminins Bind Cells to the Basal Lamina
		Integrins Are Cell Surface Receptors That Bind ECM Components
		The Dystrophin/Dystroglycan Complex Stabilizes Attachments of Muscle Cells to the ECM
	15.3 The Plant Cell Surface
		Cell Walls Provide a Structural Framework and Serve as a Permeability Barrier
		The Plant Cell Wall Is a Network of Cellulose Microfibrils, Polysaccharides, and Glycoproteins
		Cell Walls Are Synthesized in Several Discrete Stages
		Plasmodesmata Permit Direct Cell-Cell Communication Through the Cell Wall
	Summary of Key Points
	Problem Set
	Human Connections: The Costly Effects of Weak Adhesion
	Key Technique: Building an ECM from Scratch
Chapter 16. The Structural Basis of Cellular Information: DNA, Chromosomes, and the Nucleus
	16.1 Chemical Nature of the Genetic Material
		The Discovery of DNA Led to Conflicting Proposals Concerning the Chemical Nature of Genes
		Avery, MacLeod, and McCarty Showed That DNA Is the Genetic Material of Bacteria
		Hershey and Chase Showed That DNA Is the Genetic Material of Viruses
		RNA Is the Genetic Material in Some Viruses
	16.2 DNA Structure
		Chargaff ’s Rules Reveal That A = T and G = C
		Watson and Crick Discovered That DNA Is a Double Helix
		DNA Can Be Interconverted Between Relaxed and Supercoiled Forms
		The Two Strands of a DNA Double Helix Can Be Denatured and Renatured
	16.3 DNA Packaging
		Bacteria Package DNA in Bacterial Chromosomes and Plasmids
		Eukaryotes Package DNA in Chromatin and Chromosomes
		Nucleosomes Are the Basic Unit of Chromatin Structure
		A Histone Octamer Forms the Nucleosome Core
		Nucleosomes Are Packed Together to Form Chromatin Fibers and Chromosomes
		Changes in Histones and Chromatin Remodeling Proteins Can Alter Chromatin Packing
		Chromosomal DNA Contains Euchromatin and Heterochromatin
		Some Heterochromatin Plays a Structural Role in Chromosomes
		Chromosomes Can Be Identified by Unique Banding Patterns
		Eukaryotic Chromosomes Contain Large Amounts of Repeated DNA Sequences
		Eukaryotes Package Some of Their DNA in Mitochondria and Chloroplasts
	16.4 The Nucleus
		A Double-Membrane Nuclear Envelope Surrounds the Nucleus
		Molecules Enter and Exit the Nucleus Through Nuclear Pores
		The Nucleus Is Mechanically Integrated with the Rest of the Cell
		Chromatin Is Located Within the Nucleus in a Nonrandom Fashion
		The Nucleolus Is Involved in Ribosome Formation
	Summary of Key Points
	Problem Set
	Key Technique: FISHing for Specific Sequences
	Human Connections: Lamins and Premature Aging
Chapter 17. DNA Replication, Repair, and Recombination
	17.1 DNA Replication
		DNA Synthesis Occurs During S Phase
		DNA Replication Is Semiconservative
		DNA Replication Is Usually Bidirectional
		Replication Initiates at Specialized DNA Elements
		DNA Polymerases Catalyze the Elongation of DNA Chains
		DNA Is Synthesized as Discontinuous Segments That Are Joined Together by DNA Ligase
		In Bacteria, Proofreading Is Performed by the 3'→5' Exonuclease Activity of DNA Polymerase
		RNA Primers Initiate DNA Replication
		The DNA Double Helix Must Be Locally Unwound During Replication
		DNA Unwinding and DNA Synthesis Are Coordinated on Both Strands via the Replisome
		Eukaryotes Disassemble and Reassemble Nucleosomes as Replication Proceeds
		Telomeres Solve the DNA End-Replication Problem
	17.2 DNA Damage and Repair
		Mutations Can Occur Spontaneously During Replication
		Mutagens Can Induce Mutations
		DNA Repair Systems Correct Many Kinds of DNA Damage
	17.3 Homologous Recombination and Mobile Genetic Elements
		Homologous Recombination Is Initiated by Double-Strand Breaks in DNA
		Transposons Are Mobile Genetic Elements
		Transposons Differ Based on Their Autonomy and Mechanism of Movement
		Bacterial DNA-Only Transposons Can Be Composite or Noncomposite
		Eukaryotes Also Have DNA-Only Transposons
		Retrotransposons
	Summary of Key Points
	Problem Set
	Human Connections: Children of The Moon
	Key Technique: CRISPR/Cas9 Genome Editing
Chapter 18. Gene Expression: I. Transcription
	18.1 The Directional Flow of Genetic Information
		Transcription and Translation Involve Many of the Same Components in Prokaryotes and Eukaryotes
		Where Transcription and Translation Occur Differs in Prokaryotes and Eukaryotes
		In Some Cases RNA Is Reversed Transcribed into DNA
	18.2 Mechanisms of Transcription
		Transcription Involves Four Stages: RNA Polymerase Binding, Initiation, Elongation, and Termination
		Bacterial Transcription Involves ˜ Factor Binding, Initiation, Elongation, and Termination
		Transcription in Eukaryotic Cells Has Additional Complexity Compared with Prokaryotes
		RNA Polymerases I, II, and III Carry Out Transcription in the Eukaryotic Nucleus
		Three Classes of Promoters Are Found in Eukaryotic Nuclear Genes, One for Each Type of RNA Polymerase
		General Transcription Factors Are Involved in the Transcription of All Nuclear Genes
		Elongation, Termination, and RNA Cleavage Are Involved in Completing Eukaryotic RNA Synthesis
	18.3 RNA Processing and Turnover
		The Nucleolus Is Involved in Ribosome Formation
		Ribosomal RNA Processing Involves Cleavage of Multiple rRNAs from a Common Precursor
		Transfer RNA Processing Involves Removal, Addition, and Chemical Modification of Nucleotides
		Messenger RNA Processing in Eukaryotes Involves Capping, Addition of Poly(A), and Removal of Introns
		Spliceosomes Remove Introns from Pre-mRNA
		Some Introns Are Self-Splicing
		The Existence of Introns Permits Alternative Splicing and Exon Shuffling
		Cells Localize Nuclear RNAs in Several Types of Processing Centers
		Nucleic Acid Editing Allows Sequences to Be Altered
		The C-Terminal Domain of RNA Polymerase II Coordinates RNA Processing
		Nuclear Export of Mature mRNA
		Most mRNA Molecules Have a Relatively Short Life Span
		The Abundance of mRNA Allows Amplification of Genetic Information
	Summary of Key Points
	Problem Set
	Key Technique: Hunting for DNA-Protein Interactions
	Human Connections: Death by Fungus (Amanita PhalloidesPoisoning)
Chapter 19. Gene Expression: II. The Genetic Code and Protein Synthesis
	19.1 The Genetic Code
		The Genetic Code Is a Triplet Code
		The Genetic Code Is Degenerate and Nonoverlapping
		Messenger RNA Guides the Synthesis of Polypeptide Chains
		The Codon Dictionary Was Established Using Synthetic RNA Polymers and Triplets
		Of the 64 Possible Codons in Messenger RNA, 61 Encode Amino Acids
		The Genetic Code Is (Nearly) Universal
		Codon Usage Bias
	19.2 Translation: The Cast of Characters
		Ribosomes Carry Out Polypeptide Synthesis
		Transfer RNA Molecules Bring Amino Acids to the Ribosome
		Aminoacyl-tRNA Synthetases Link Amino Acids to the Correct Transfer RNAs
		Messenger RNA Brings Polypeptide Coding Information to the Ribosome
		Protein Factors Are Required for Translational Initiation, Elongation, and Termination
	19.3 The Mechanism of Translation
		Translational Initiation Requires Initiation Factors, Ribosomal Subunits, mRNA, and Initiator tRNA
		Chain Elongation Involves Cycles of Aminoacyl tRNA Binding, Peptide Bond Formation, and Translocation
		Most mRNAs Are Read by Many Ribosomes Simultaneously
		Termination of Polypeptide Synthesis Is Triggered by Release Factors That Recognize Stop Codons
		Polypeptide Folding Is Facilitated by Molecular Chaperones
		Protein Synthesis Typically Utilizes a Substantial Fraction of a Cell’s Energy Budget
		A Summary of Translation
	19.4 Mutations and Translation
		Suppressor tRNAs Overcome the Effects of Some Mutations
		Nonsense-Mediated Decay and Nonstop Decay Promote the Destruction of Defective mRNAs
	19.5 Posttranslational Processing
	Summary of Key Points
	Problem Set
	Human Connections: To Catch a Killer: The Problem of Antibiotic Resistance In Bacteria
	Key Technique: Protein Localization Using Fluorescent Fusion Proteins
Chapter 20. The Regulation of Gene Expression
	20.1 Bacterial Gene Regulation
		Catabolic and Anabolic Pathways Are Regulated Through Induction and Repression, Respectively
		The Genes Involved in Lactose Catabolism Are Organized into an Inducible Operon
		The lac Operon Is Negatively Regulated by the lac Repressor
		Studies of Mutant Bacteria Revealed How the lac Operon Is Organized
		Catabolite Activator Protein (CAP) Positively Regulates the lac Operon
		The lac Operon Is an Example of the Dual Control of Gene Expression
		The Structure of the lac Repressor/Operator Complex Confirms the Operon Model
		The Genes Involved in Tryptophan Synthesis Are Organized into a Repressible Operon
		Sigma Factors Determine Which Sets of Genes Can Be Expressed
		Attenuation Allows Transcription to Be Regulated After the Initiation Step
		Riboswitches Allow Transcription and Translation to Be Controlled by Small-Molecule Interactions with RNA
		The CRISPR/Cas System Protects Bacteria Against Viral Infection
	20.2 Eukaryotic Gene Regulation: Genomic Control
		Multicellular Eukaryotes Are Composed of Numerous Specialized Cell Types
		Eukaryotic Gene Expression Is Regulated at Five Main Levels
		The Cells of a Multicellular Organism Usually Contain the Same Set of Genes
		Gene Amplification and Deletion Can Alter the Genome
		DNA Rearrangements Can Alter the Genome
		Chromatin Decondensation Is Involved in Genomic Control
		DNA Methylation Is Associated with Inactive Regions of the Genome
	20.3 Eukaryotic Gene Regulation: Transcriptional Control
		Different Sets of Genes Are Transcribed in Different Cell Types
		Proximal Control Elements Lie Close to the Promoter
		Enhancers and Silencers Are DNA Elements Located at Variable Distances from the Promoter
		Coactivators Mediate the Interaction Between Regulatory Transcription Factors and the RNA Polymerase Complex
		Multiple DNA Control Elements and Transcription Factors Act in Combination
		DNA-Binding and Activation Domains of Regulatory Transcription Factors Are Functionally Separable
		Several Common Types of Transcription Factors Bind to DNA and Activate Transcription
		DNA Response Elements Coordinate the Expression of Nonadjacent Genes
		Steroid Hormone Receptors Act as Transcription Factors That Bind to Hormone Response Elements
		CREBs and STATs Are Examples of Transcription Factors Activated by Phosphorylation
		The Heat Shock Response Element Coordinates Stress Responses
		Homeotic Genes Encode Transcription Factors That Regulate Embryonic Development
	20.4 Eukaryotic Gene Regulation: Posttranscriptional Control
		Control of RNA Processing and Nuclear Export Follows Transcription
		Translation Rates Can Be Controlled by Initiation Factors and Translational Repressors
		Translation Can Also Be Controlled by Regulation of mRNA Degradation
		RNA Interference Utilizes Small RNAs to Silence Gene Expression
		MicroRNAs Produced by Normal Cellular Genes Silence the Translation of mRNAs
		Piwi-Interacting RNAs Are Small Regulatory RNAs That Protect the Germline of Eukaryotes
		Long Noncoding RNAs Play a Variety of Roles in Eukaryotic Gene Regulation
		Posttranslational Control Involves Modifications of Protein Structure, Function, and Degradation
		Ubiquitin Targets Proteins for Degradation by Proteasomes
		A Summary of Eukaryotic Gene Regulation
	Summary of Key Points
	Problem Set
	Human Connections: The Epigenome: Methylation and Disease
	Key Technique: Gene Knockdown via RNAi
Chapter 21. Molecular Biology Techniques for Cell Biology
	21.1 Analyzing, Manipulating, and Cloning DNA
		PCR Is Widely Used to Clone Genes
		Restriction Endonucleases Cleave DNA Molecules at Specific Sites
		Gel Electrophoresis Allows DNA to Be Separated by Size
		Restriction Mapping Can Characterize DNA
		Southern Blotting Identifies Specific DNAs from a Mixture
		Restriction Enzymes Allow Production of Recombinant DNA
		DNA Cloning Can Use Bacterial Cloning Vectors
		Genomic and cDNA Libraries Are Both Useful for DNA Cloning
	21.2 Sequencing and Analyzing Genomes
		Rapid Procedures Exist for DNA Sequencing
		Whole Genomes Can Be Sequenced
		Comparative Genomics Allows Comparison of Genomes and Genes Within Them
		The Field of Bioinformatics Helps Decipher Genomes
		Tiny Differences in Genome Sequence Distinguish People from One Another
	21.3 Analyzing RNA and Proteins
		Several Techniques Allow Detection of mRNAs in Time and Space
		The Transcription of Thousands of Genes Can Be Assessed Simultaneously
		Proteins Can Be Studied Using Electrophoresis
		Antibodies Can Be Used to Study Specific Proteins
		Proteins Can Be Isolated by Size, Charge, or Affinity
		Proteins Can Be Identified from Complex Mixtures Using Mass Spectrometry
		Protein Function Can Be Studied Using Molecular Biology Techniques
		Protein-Protein Interactions Can Be Studied in a Variety of Ways
	21.4 Analyzing and Manipulating Gene Function
		Transgenic Organisms Carry Foreign Genes That Are Passed on to Subsequent Generations
		Transcriptional Reporters Are Useful for Studying Regulation of Gene Expression
		The Role of Specific Genes Can Be Assessed By Identifying Mutations and by Knockdown
		Genetic Engineering Can Produce Valuable Proteins That Are Otherwise Difficult to Obtain
		Food Crops Can Be Genetically Modified
		Gene Therapies Are Being Developed for the Treatment of Human Diseases
	Summary of Key Points
	Problem Set
	Key Technique: The Polymerase Chain Reaction (PCR)
	Human Connections: More Than Your Fingertips: Identifying Genetic “Fingerprints”
Chapter 22. Signal Transduction Mechanisms: I. Electrical and Synaptic Signaling in Neurons
	22.1 Neurons and Membrane Potential
		Neurons Are Specially Adapted to Transmit Electrical Signals
		Neurons Undergo Changes in Membrane Potential
		Neurons Display Electrical Excitability
		Resting Membrane Potential Depends on Ion Concentrations and Selective Membrane Permeability
		The Nernst Equation Describes the Relationship Between Membrane Potential and Ion Concentration
		Steady-State Ion Concentrations Affect Resting Membrane Potential
		The Goldman Equation Describes the Combined Effects of Ions on Membrane Potential
	22.2 Electrical Excitability and the Action Potential
		Patch Clamping and Molecular Biological Techniques Allow Study of Single Ion Channels
		Specific Domains of Voltage-Gated Channels Act as Sensors and Inactivators
		Action Potentials Propagate Electrical Signals Along an Axon
		Action Potentials Involve Rapid Changes in the Membrane Potential of the Axon
		Action Potentials Result from the Rapid Movement of Ions Through Axonal Membrane Channels
		Action Potentials Are Propagated Along the Axon Without Losing Strength
		The Myelin Sheath Acts Like an Electrical Insulator Surrounding the Axon
	22.3 Synaptic Transmission and Signal Integration
		Neurotransmitters Relay Signals Across Nerve Synapses
		Elevated Calcium Levels Stimulate Secretion of Neurotransmitters from Presynaptic Neurons
		Secretion of Neurotransmitters Involves the Docking and Fusion of Vesicles with the Plasma Membrane
		Neurotransmitters Are Detected by Specific Receptors on Postsynaptic Neurons
		Neurotransmitters Must Be Inactivated Shortly After Their Release
		Postsynaptic Potentials Integrate Signals from Multiple Neurons
	Summary of Key Points
	Problem Set
	Key Technique: Patch Clamping
	Human Connections: The Toxic Price of the Fountain of Youth
Chapter 23. Signal Transduction Mechanisms: II. Messengers and Receptors
	23.1 Chemical Signals and Cellular Receptors
		Chemical Signaling Involves Several Key Components
		Receptor Binding Involves Quantitative Interactions Between Ligands and Their Receptors
		Cells Can Amplify Signals Once They Are Received
		Cell-Cell Signals Act Through a Limited Number of Receptors and Signal Transduction Pathways
	23.2 G Protein–Coupled Receptors
		G Protein–Coupled Receptors Act via Hydrolysis of GTP
		Cyclic AMP Is a Second Messenger Whose Production Is Regulated by Some G Proteins
		Disruption of G Protein Signaling Causes Human Disease
		Many G Proteins Act Through Inositol Trisphosphate and Diacylglycerol
		The Release of Calcium Ions Is a Key Event in Many Signaling Processes
	23.3 Enzyme-Coupled Receptors
		Growth Factors Often Bind Protein Kinase-Associated Receptors
		Receptor Tyrosine Kinases Aggregate and Undergo Autophosphorylation
		Receptor Tyrosine Kinases Initiate a Signal Transduction Cascade Involving Ras and MAP Kinase
		The Key Steps in RTK Signaling Can Be Dissected Using Mutants
		Receptor Tyrosine Kinases Activate a Variety of Other Signaling Pathways
		Other Growth Factors Transduce Their Signals via Receptor Serine-Threonine Kinases
		Other Enzyme-Coupled Receptors Families
	23.4 Putting It All Together: Signal Integration
		Scaffolding Complexes Can Facilitate Cell Signaling
		Different Signaling Pathways Are Integrated Through Crosstalk
	23.5 Hormones and Other Long-Range Signals
		Hormones Can Be Classified by Their Chemical Properties
		The Endocrine System Controls Multiple Signaling Pathways to Regulate Glucose Levels
		Steroid Hormones Bind Hormones in the Cytosol and Carry Them into the Nucleus
		Gases Can Act as Cell Signals
	Summary of Key Points
	Problem Set
	Key Technique: Calcium Indicators and Ionophores
	Human Connections: The Gas That Prevents a Heart Attack
Chapter 24. The Cell Cycle and Mitosis
	24.1 Overview of the Cell Cycle
	24.2 Nuclear and Cell Division
		Mitosis Is Subdivided into Prophase, Prometaphase, Metaphase, Anaphase, and Telophase
		The Mitotic Spindle Is Responsible for Chromosome Movements During Mitosis
		Cytokinesis Divides the Cytoplasm
		Bacteria and Eukaryotic Organelles Divide in a Different Manner from Eukaryotic Cells
	24.3 Regulation of the Cell Cycle
		Cell Cycle Length Varies Among Different Cell Types
		Cell Cycle Progression Is Controlled at Several Key Transition Points
		Cell Fusion Experiments and Cell Cycle Mutants Identified Molecules That Control the Cell Cycle
		The Cell Cycle Is Controlled by Cyclin-Dependent Kinases (Cdks)
		Cdk-Cyclin Complexes Are Tightly Regulated
		The Anaphase-Promoting Complex Allows Exit from Mitosis
		Checkpoint Pathways Monitor Key Steps in the Cell Cycle
	24.4 Growth Factors and Cell Proliferation
		Stimulatory Growth Factors Activate the Ras Pathway
		Stimulatory Growth Factors Can Also Activate the PI 3-Kinase–Akt Pathway
		Inhibitory Growth Factors Act Through Cdk Inhibitors
		Putting It All Together: The Cell Cycle Regulation Machine
	24.5 Apoptosis
		Apoptosis Is Triggered by Death Signals or Withdrawal of Survival Factors
	Summary of Key Points
	Problem Set
	Key Technique: Measuring Cells Millions at a Time
	Human Connections: What do Ethnobotany and Cancer Have in Common?
Chapter 25. Sexual Reproduction, Meiosis, and Genetic Recombination
	25.1 Sexual Reproduction
		Sexual Reproduction Produces Genetic Variety
		Gametes Are Haploid Cells Specialized for Sexual Reproduction
	25.2 Meiosis
		The Life Cycles of Sexual Organisms Have Diploid and Haploid Phases
		Meiosis Converts One Diploid Cell into Four Haploid Cells
		Meiosis I Produces Two Haploid Cells That Have Chromosomes Composed of Sister Chromatids
		Meiosis II Resembles a Mitotic Division
		Defects in Meiosis Lead to Nondisjunction
		Sperm and Egg Cells Are Generated by Meiosis Accompanied by Cell Differentiation
		Meiotic Maturation of Oocytes Is Tightly Regulated
	25.3 Genetic Variability: Segregation and Assortment of Alleles
		Meiosis Generates Genetic Diversity
		Information Specifying Recessive Traits Can Be Present Without Being Displayed
		Alleles of Each Gene Segregate from Each Other During Gamete Formation
		Alleles of Each Gene Segregate Independently of the Alleles of Other Genes
		Chromosome Behavior Explains the Laws of Segregation and Independent Assortment
		The DNA Molecules of Homologous Chromosomes Have Similar Base Sequences
	25.4 Genetic Variability: Recombination and Crossing Over
		Chromosomes Contain Groups of Linked Genes That Are Usually Inherited Together
		Homologous Chromosomes Exchange Segments During Crossing Over
		Gene Locations Can Be Mapped by Measuring Recombination Frequencies
	25.5 Genetic Recombination in Bacteria and Viruses
		Co-infection of Bacterial Cells with Related Bacteriophages Can Lead to Genetic Recombination
		Recombination in Bacteria Can Occur via Transformation or Transduction
		Conjugation Is a Modified Sexual Activity That Facilitates Genetic Recombination in Bacteria
	25.6 Mechanisms of Homologous Recombination
		DNA Breakage and Exchange Underlie Homologous Recombination Between Chromosomes
		The Synaptonemal Complex Facilitates Homologous Recombination During Meiosis
		Homologous Recombination Between Chromosomes Relies on High-Fidelity DNA Repair
	Summary of Key Points
	Problem Set
	Human Connections: When Meiosis Goes Awry
	Key Technique: Using Mendel’s Rules to Predict Human Disease
Chapter 26. Cancer Cells
	26.1 How Cancers Arise
		Tumors Arise When the Balance Between Cell Division and Cell Differentiation or Death Is Disrupted
		Cancer Cell Proliferation Is Anchorage Independent and Insensitive to Population Density
		Cancer Cells Are Immortalized by Mechanisms That Maintain Telomere Length
		Defects in Signaling Pathways, Cell Cycle Controls, and Apoptosis Contribute to Cancer
		Cancer Arises Through a Multistep Process Involving Initiation, Promotion, and Tumor Progression
	26.2 How Cancers Spread
		Angiogenesis Is Required for Tumors to Grow Beyond a Few Millimeters in Diameter
		Blood Vessel Growth Is Controlled by a Balance Between Angiogenesis Activators and Inhibitors
		Cancer Cells Spread by Invasion and Metastasis
		Changes in Cell Adhesion, Motility, and Protease Production Promote Metastasis
		Relatively Few Cancer Cells Survive the Voyage Through the Bloodstream
		Blood Flow and Organ-Specific Factors Determine Sites of Metastasis
		The Immune System Influences the Growth and Spread of Cancer Cells
		The Tumor Microenvironment Influences Tumor Growth, Invasion, and Metastasis
	26.3 What Causes Cancer?
		Epidemiological Data Have Allowed Many Causes of Cancer to Be Identified
		Errors in DNA Replication or Repair Explain Many Cancers
		Inborn Errors Explain Some Cancers
		Many Chemicals Can Cause Cancer, Often After Metabolic Activation in the Liver
		DNA Mutations Triggered by Chemical Carcinogens Lead to Cancer
		Ionizing and Ultraviolet Radiation Also Cause DNA Mutations That Lead to Cancer
		Viruses and Other Infectious Agents Trigger the Development of Some Cancers
	26.4 Oncogenes and Tumor Suppressor Genes
		Oncogenes Are Genes Whose Products Can Trigger the Development of Cancer
		Proto-oncogenes Are Converted into Oncogenes by Several Distinct Mechanisms
		Most Oncogenes Encode Components of Growth-Signaling Pathways
		Tumor Suppressor Genes Are Genes Whose Loss or Inactivation Can Lead to Cancer
		The RB Tumor Suppressor Gene Was Discovered by Studying Families with Hereditary Retinoblastoma
		The p53 Tumor Suppressor Gene Is the Most Frequently Mutated Gene in Human Cancers
		The APC Tumor Suppressor Gene Encodes a Protein That Inhibits the Wnt Signaling Pathway
		Inactivation of Some Tumor Suppressor Genes Leads to Genetic Instability
		Cancers Develop by the Stepwise Accumulation of Mutations Involving Oncogenes and Tumor Suppressor Genes
		Epigenetic Changes in Gene Expression Influence the Properties of Cancer Cells
		Summing Up: Carcinogenesis and the Hallmarks of Cancer
	26.5 Diagnosis, Screening, and Treatment
		Cancer Is Diagnosed by Microscopic and Molecular Examination of Tissue Specimens
		Screening Techniques for Early Detection Can Prevent Cancer Deaths
		Surgery, Radiation, and Chemotherapy Are Standard Treatments for Cancer
		Molecular Targeting Can Attack Cancer Cells More Specifically Than Chemotherapy
		Using the Immune System to Target Cancer Cells
		Cancer Treatments Can Be Tailored to Individual Patients
	Summary of Key Points
	Problem Set
	Human Connections: Molecular Sleuthing in Cancer Diagnosis
	Key Technique: Targeting Molecules in the Fight Against Cancer
Appendix Visualizing Cells And Molecules
Answer Key To Concept Check And Key Technique Questions
Glossary
Photo, Illustration, And Text Credits
Index
	A
	B
	C
	D
	E
	F
	G
	H
	I
	J
	K
	L
	M
	N
	O
	P
	Q
	R
	S
	T
	U
	V
	W
	X
	Y
	Z