Essential Cell Biology

Table Of Contents:

Chapter 1 Introduction to Cells 1(36)

Cells Under the Microscope 1(8)

The Invention of the Light Microscope Led to the Discovery of Cells 2(1)

Cells, Organelles, and Even Molecules Can Be Seen Under the Microscope 3(6)

The Eucaryotic Cell 9(8)

The Nucleus Is the Information Store of the Cell 9(1)

Mitochondria Generate Energy from Food to Power the Cell 10(2)

Chloroplasts Capture Energy from Sunlight 12(1)

Internal Membranes Create Intracellular Compartments with Different Functions 13(2)

The Cytosol Is a Concentrated Aqueous Gel of Large and Small Molecules 15(1)

The Cytoskeleton Is Responsible for Cell Movements 16(1)

Unity and Diversity of Cells 17(17)

Cells Vary Enormously in Appearance and Function 19(2)

Living Cells All Have a Similar Basic Chemistry 21(1)

All Present-Day Cells Have Apparently Evolved from the Same Ancestor 21(1)

Bacteria Are the Smallest and Simplest Cells 22(3)

Molecular Biologists Have Focused on E. coli 25(1)

Giardia May Represent an Intermediate Stage in the Evolution of Eucaryotic Cells 25(1)

Brewer's Yeast Is a Simple Eucaryotic Cell 26(1)

Single-celled Organisms Can Be Large, Complex, and Fierce: The Protozoans 27(1)

Arabidopsis Has Been Chosen Out of 300,000 Species as a Model Plant 28(1)

The World of Animals Is Represented by a Fly, a Worm, a Mouse, and Homo Sapiens 29(2)

Cells in the Same Multicellular Organism Can Be Spectacularly Different 31(3)

Essential Concepts 34(1)

Questions 35(2)

Chapter 2 Chemical Components of Cells 37(42)

Chemical Bonds 37(15)

Cells Are Made of Relatively Few Types of Atoms 38(1)

The Outermost Electrons Determine How Atoms Interact 39(3)

Ionic Bonds Form by the Gain and Loss of Electrons 42(1)

Covalent Bonds Form by the Sharing of Electrons 43(2)

There Are Different Types of Covalent Bonds 45(3)

Water Is the Most Abundant Substance in Cells 48(1)

Some Polar Molecules Form Acids and Bases in Water 49(3)

Molecules in Cells 52(21)

A Cell Is Formed from Carbon Compounds 52(1)

Cells Contain Four Major Families of Small Organic Molecules 52(1)

Sugars Are Energy Sources for Cells and Subunits of Polysaccharides 53(2)

Fatty Acids Are Components of Cell Membranes 55(5)

Amino Acids Are the Subunits of Proteins 60(1)

Nucleotides Are the Subunits of DNA and RNA 61(4)

Macromolecules Contain a Specific Sequence of Subunits 65(4)

Noncovalent Bonds Specify the Precise Shape of a Macromolecule 69(3)

Noncovalent Bonds Allow a Macromolecule to Bind Other Selected Molecules 72(1)

Essential Concepts 73(1)

Questions 74(5)

Chapter 3 Energy, Catalysis, and Biosynthesis 79(29)

Catalysis and the Use of Energy by Cells 79(15)

Biological Order Is Made Possible by the Release of Heat Energy from Cells 79(3)

Photosynthetic Organisms Use Sunlight to Synthesize Organic Molecules 82(1)

Cells Obtain Energy by the Oxidation of Biological Molecules 83(1)

Oxidation and Reduction Involve Electron Transfers 84(1)

Enzymes Lower the Barriers That Block Chemical Reactions 85(1)

How Enzymes Find Their Substrates: The Importance of Rapid Diffusion 86(3)

The Free-Energy Change for a Reaction Determines Whether It Can Occur 89(1)

The Concentration of Reactants Influences XXXG 89(4)

For Sequential Reactions, XXXG(0) Values Are Additive 93(1)

Activated Carrier Molecules and Biosynthesis 94(11)

The Formation of an Activated Carrier Is Coupled to an Energetically Favorable Reaction 95(1)

ATP Is the Most Widely Used Activated Carrier Molecule 96(1)

Energy Stored in ATP Is Often Harnessed to Join Two Molecules Together 97(1)

NADH and NADPH Are Important Electron Carriers 98(2)

There Are Many Other Activated Carrier Molecules in Cells 100(3)

The Synthesis of Biological Polymers Requires an Energy Input 103(2)

Essential Concepts 105(1)

Questions 106(2)

Chapter 4 How Cells Obtain Energy from Food 108(26)

The Breakdown of Sugars and Fats 108(17)

Food Molecules Are Broken Down in Three Stages to Produce ATP 108(2)

Glycolysis Is a Central ATP-producing Pathway 110(4)

Fermentations Allow ATP to Be Produced in the Absence of Oxygen 114(1)

Glycolysis Illustrates How Enzymes Couple Oxidation to Energy Storage 114(4)

Sugars and Fats Are Both Degraded to Acetyl CoA in Mitochondria 118(1)

The Citric Acid Cycle Generates NADH by Oxidizing Acetyl Groups to CO(2) 119(5)

Electron Transport Drives the Synthesis of the Majority of the ATP in Most Cells 124(1)

Storing and Utilizing Food 125(4)

Organisms Store Food Molecules in Special Reservoirs 125(2)

Many Biosynthetic Pathways Begin with Glycolysis or the Citric Acid Cycle 127(1)

Metabolism Is Organized and Regulated 128(1)

Essential Concepts 129(1)

Questions 130(4)

Chapter 5 Protein Structure and Function 134(50)

The Shape and Structure of Proteins 134(20)

The Shape of a Protein Is Specified by Its Amino Acid Sequence 134(5)

Proteins Fold into a Conformation of Lowest Energy 139(1)

Proteins Come in a Wide Variety of Complicated Shapes 140(1)

The XXX Helix and the XXX Sheet Are Common Folding Patterns 141(4)

Proteins Have Several Levels of Organization 145(2)

Few of the Many Possible Polypeptide Chains Will Be Useful 147(1)

Proteins Can Be Classified into Families 147(1)

Larger Protein Molecules Often Contain More Than One Polypeptide Chain 148(1)

Proteins Can Assemble into Filaments, Sheets, or Spheres 149(3)

A Helix Is a Common Structural Motif in Biological Structures 152(1)

Some Types of Proteins Have Elongated Fibrous Shapes 152(2)

Extracellular Proteins Are Often Stabilized by Covalent Cross-Linkages 154(1)

How Proteins Work 154(25)

Proteins Bind to Other Molecules 155(1)

The Binding Sites of Antibodies Are Especially Versatile 156(1)

Binding Strength Is Measured by the Equilibrium Constant 157(10)

Enzymes Are Powerful and Highly Specific Catalysts 167(1)

Lysozyme Illustrates How an Enzyme Works 167(2)

V(max) and K(M) Measure Enzyme Performance 169(2)

Tightly Bound Small Molecules Add Extra Functions to Proteins 171(1)

The Catalytic Activities of Enzymes Are Regulated 172(1)

Allosteric Enzymes Have Two Binding Sites That Interact 173(1)

A Conformational Change Can Be Driven by Protein Phosphorylation 174(2)

GTP-binding Proteins Can Undergo Dramatic Conformational Changes 176(1)

Motor Proteins Produce Large Movements in Cells 176(2)

Proteins Often Form Large Complexes That Function as Protein Machines 178(1)

Essential Concepts 179(1)

Questions 180(4)

Chapter 6 DNA 184(28)

The Structure and Function of DNA 184(5)

Genes Are Made of DNA 185(1)

A DNA Molecule Consists of Two Complementary Chains of Nucleotides 185(3)

The Structure of DNA Provides a Mechanism for Heredity 188(1)

DNA Replication 189(9)

DNA Synthesis Begins at Replication Origins 190(1)

New DNA Synthesis Occurs at Replication Forks 191(2)

The Replication Fork Is Asymmetrical 193(1)

DNA Polymerase Is Self-correcting 194(1)

Short Lengths of RNA Act as Primers for DNA Synthesis 194(2)

Proteins at a Replication Fork Cooperate to Form a Replication Machine 196(2)

DNA Repair 198(8)

Changes in DNA Are the Cause of Mutations 198(2)

A DNA Mismatch Repair System Removes Replication Errors That Escape from the Replication Machine 200(1)

DNA Is Continually Suffering Damage in Cells 201(1)

The Stability of Genes Depends on DNA Repair 202(3)

The High Fidelity with Which DNA Is Maintained Means That Closely Related Species Have Proteins with Very Similar Sequences 205(1)

Essential Concepts 206(1)

Questions 207(5)

Chapter 7 From DNA to Protein 212(34)

From DNA to RNA 212(12)

Portions of DNA Sequence Are Transcribed into RNA 212(1)

Transcription Produces RNA Complementary to One Strand of DNA 213(2)

Several Types of RNA Are Produced in Cells 215(1)

Signals in DNA Tell RNA Polymerase Where to Start and Finish 216(2)

Eucaryotic RNAs Undergo Processing in the Nucleus 218(1)

Eucaryotic Genes Are Interrupted by Noncoding Sequences 219(1)

Introns Are Removed by RNA Splicing 220(2)

mRNA Molecules Are Eventually Degraded by the Cell 222(1)

The Earliest Cells May Have Had Introns in Their Genes 223(1)

From RNA to Protein 224(10)

An mRNA Sequence Is Decoded in Sets of Three Nucleotides 224(1)

tRNA Molecules Match Amino Acids to Codons in mRNA 225(2)

Specific Enzymes Couple tRNAs to the Correct Amino Acid 227(1)

The RNA Message Is Decoded on Ribosomes 227(3)

Codons in mRNA Signal Where to Start and to Stop Protein Synthesis 230(2)

Proteins Are Made on Polyribosomes 232(1)

Carefully Controlled Protein Breakdown Helps Regulate the Amount of Each Protein in a Cell 232(2)

There Are Many Steps Between DNA and Protein 234(1)

RNA and the Origins of Life 234(6)

Simple Biological Molecules Can Form Under Prebiotic Conditions 235(2)

RNA Can Both Store Information and Catalyze Chemical Reactions 237(2)

RNA Is Thought to Predate DNA in Evolution 239(1)

Essential Concepts 240(1)

Questions 241(5)

Chapter 8 Chromosomes and Gene Regulation 246(32)

The Structure of Eucaryotic Chromosomes 246(11)

Eucaryotic DNA Is Packaged into Chromosomes 246(1)

Chromosomes Exist in Different States Throughout the Life of a Cell 247(2)

Specialized DNA Sequences Ensure That Chromosomes Replicate Efficiently 249(1)

Nucleosomes Are the Basic Units of Chromatin Structure 250(2)

Chromosomes Have Several Levels of DNA Packing 252(1)

Interphase Chromosomes Contain Both Condensed and More Extended Forms of Chromatin 253(3)

Position Effects on Gene Expression Reveal Differences in Interphase Chromosome Packing 256(1)

Interphase Chromosomes Are Organized Within the Nucleus 256(1)

Gene Regulation 257(17)

Cells Regulate the Expression of Their Genes 258(1)

Transcription Is Controlled by Proteins Binding to Regulatory DNA Sequences 259(2)

Repressors Turn Genes Off and Activators Turn Them On 261(2)

Initiation of Eucaryotic Gene Transcription Is a Complex Process 263(1)

Eucaryotic RNA Polymerase Requires General Transcription Factors 264(1)

Eucaryotic Gene Regulatory Proteins Control Gene Expression from a Distance 265(1)

Packing of Promoter DNA into Nucleosomes Can Affect Initiation of Transcription 266(1)

Eucaryotic Genes Are Regulated by Combinations of Proteins 267(1)

The Expression of Different Genes Can Be Coordinated by a Single Protein 268(1)

Combinatorial Control Can Create Different Cell Types 269(2)

Stable Patterns of Gene Expression Can Be Transmitted to Daughter Cells 271(2)

The Formation of an Entire Organ Can Be Triggered by a Single Gene Regulatory Protein 273(1)

Essential Concepts 274(1)

Questions 275(3)

Chapter 9 Genetic Variation 278(37)

Genetic Variation in Bacteria 278(13)

The Rapid Rate of Bacterial Division Means That Mutation Will Occur Over a Short Time Period 279(1)

Mutation in Bacteria Can Be Selected by a Change in Environmental Conditions 280(1)

Bacterial Cells Can Acquire Genes from Other Bacteria 281(1)

Bacterial Genes Can Be Transferred by a Process Called Bacterial Mating 282(2)

Some Bacteria Can Take Up DNA from Their Surroundings 284(1)

Gene Exchange Occurs by Homologous Recombination Between Two DNA Molecules of Similar Nucleotide Sequence 285(3)

Genes Can Be Transferred Between Bacteria by Bacterial Viruses 288(1)

Transposable Elements Create Genetic Diversity 289(2)

Sources of Genetic Change in Eucaryotic Genomes 291(13)

Random DNA Duplications Create Families of Related Genes 292(1)

Genes Encoding New Proteins Can Be Created by the Recombination of Exons 293(1)

A Large Part of the DNA of Multicellular Eucaryotes Consists of Repeated, Noncoding Sequences 294(1)

About 10% of the Human Genome Consists of Two Families of Transposable Sequences 295(1)

The Evolution of Genomes Has Been Accelerated by Transposable Elements 296(1)

Viruses Are Fully Mobile Genetic Elements That Can Escape from Cells 297(3)

Retroviruses Reverse the Normal Flow of Genetic Information 300(2)

Retroviruses That Have Picked Up Host Genes Can Make Cells Cancerous 302(2)

Sexual Reproduction and the Reassortment of Genes 304(5)

Sexual Reproduction Gives a Competitive Advantage to Organisms in an Unpredictably Variable Environment 304(1)

Sexual Reproduction Involves Both Diploid and Haploid Cells 305(1)

Meiosis Generates Haploid Cells from Diploid Cells 306(1)

Meiosis Generates Enormous Genetic Variation 307(2)

Essential Concepts 309(1)

Questions 310(5)

Chapter 10 DNA Technology 315(33)

How DNA Molecules Are Analyzed 315(5)

Restriction Nucleases Cut DNA Molecules at Specific Sites 315(2)

Gel Electrophoresis Separates DNA Fragments of Different Sizes 317(3)

The Nucleotide Sequence of DNA Fragments Can Be Determined 320(1)

Nucleic Acid Hybridization 320(4)

DNA Hybridization Facilitates the Prenatal Diagnosis of Genetic Diseases 321(2)

In Situ Hybridization Locates Nucleic Acid Sequences in Cells or on Chromosomes 323(1)

DNA Cloning 324(11)

DNA Ligase Joins DNA Fragments Together to Produce a Recombinant DNA Molecule 325(1)

Bacterial Plasmids Can Be Used to Clone DNA 326(1)

Human Genes Are Isolated by DNA Cloning 327(2)

cDNA Libraries Represent the mRNA Produced by a Particular Tissue 329(2)

Hybridization Allows Even Distantly Related Genes to Be Identified 331(1)

The Polymerase Chain Reaction Amplifies Selected DNA Sequences 332(3)

DNA Engineering 335(7)

Completely Novel DNA Molecules Can Be Constructed 335(2)

Rare Cellular Proteins Can Be Made in Large Amounts Using Cloned DNA 337(1)

RNAs Can Be Produced by Transcription in Vitro 338(1)

Mutant Organisms Best Reveal the Function of a Gene 339(1)

Transgenic Animals Carry Engineered Genes 340(2)

Essential Concepts 342(1)

Questions 343(5)

Chapter 11 Membrane Structure 348(24)

The Lipid Bilayer 348(9)

Membrane Lipids Form Bilayers in Water 349(3)

The Lipid Bilayer Is a Two-dimensional Fluid 352(1)

The Fluidity of a Lipid Bilayer Depends on Its Composition 353(1)

The Lipid Bilayer Is Asymmetrical 354(1)

Lipid Asymmetry Is Generated Inside the Cell 355(1)

Lipid Bilayers Are Impermeable to Solutes and Ions 356(1)

Membrane Proteins 357(11)

Membrane Proteins Associate with the Lipid Bilayers in Various Ways 358(1)

A Polypeptide Chain Usually Crosses the Bilayer as an XXX Helix 358(2)

Membrane Proteins Can Be Solubilized in Detergents and Purified 360(1)

The Complete Structure Is Known for Very Few Membrane Proteins 361(2)

The Plasma Membrane Is Reinforced by the Cell Cortex 363(1)

The Cell Surface Is Coated with Carbohydrate 364(2)

Cells Can Restrict the Movement of Membrane Proteins 366(2)

Essential Concepts 368(1)

Questions 368(5)

Chapter 12 Membrane Transport 372(37)

The Ion Concentrations Inside a Cell Are Very Different from Those Outside 372(1)

Carrier Proteins and Their Functions 373(12)

Solutes Cross Membranes by Passive or Active Transport 375(1)

Electrical Forces as Well as Concentration Gradients Can Drive Passive Transport 375(2)

Active Transport Moves Solutes Against Their Electrochemical Gradients 377(1)

Animal Cells Use the Energy of ATP Hydrolysis to Pump Out Na+ 378(1)

The Na(+)-K(+) Pump Is Driven by the Transient Addition of a Phosphate Group 379(1)

Animal Cells Use the Na(+) Gradient to Take Up Nutrients Actively 380(1)

The Na(+)-K(+) Pump Helps Maintain the Osmotic Balance of Animal Cells 381(2)

Intracellular Ca(2+) Concentrations Are Kept Low by Ca(2+) Pumps 383(1)

H(+) Gradients Are Used to Drive Membrane Transport in Plants, Fungi, and Bacteria 384(1)

Ion Channels and the Membrane Potential 385(9)

Ion Channels Are Ion Selective and Gated 386(2)

Ion Channels Randomly Snap Between Open and Closed States 388(2)

Voltage-gated Ion Channels Respond to the Membrane Potential 390(1)

The Membrane Potential Is Governed by Membrane Permeability to Specific Ions 391(3)

Ion Channels and Signaling in Nerve Cells 394(10)

Action Potentials Provide for Rapid Long-Distance Communication 395(1)

Action Potentials Are Usually Mediated by Voltage-gated Na(+) Channels 395(2)

Voltage-gated Ca(2+) Channels Convert Electrical Signals into Chemical Signals at Nerve Terminals 397(2)

Transmitter-gated Channels in Target Cells Convert Chemical Signals Back into Electrical Signals 399(1)

Neurons Receive Both Excitatory and Inhibitory Inputs 400(1)

Synaptic Connections Enable You to Think, Act, and Remember 401(3)

Essential Concepts 404(1)

Questions 405(4)

Chapter 13 Energy Generation in Mitochondria and Chloroplasts 409(39)

Cells Obtain Most of Their Energy by a Membrane-based Mechanism 409(1)

Mitochondria and Oxidative Phosphorylation 410(11)

A Mitochondrion Contains Two Membrane-bounded Compartments 411(2)

High-Energy Electrons Are Generated via the Citric Acid Cycle 413(1)

Electrons Are Transferred Along a Chain of Proteins in the Inner Mitochondrial Membrane 414(1)

Electron Transport Generates a Proton Gradient Across the Membrane 415(2)

The Proton Gradient Drives ATP Synthesis 417(2)

Coupled Transport Across the Inner Mitochondrial Membrane Is Driven by the Electrochemical Proton Gradient 419(1)

Proton Gradients Produce Most of the Cell's ATP 419(2)

The Rapid Conversion of ADP to ATP in Mitochondria Maintains a High ATP:ADP Ratio in Cells 421(1)

Electron-Transport Chains and Proton Pumping 421(9)

Protons Are Readily Moved by the Transfer of Electrons 422(1)

The Redox Potential Is a Measure of Electron Affinities 422(1)

Electron Transfers Release Large Amounts of Energy 423(2)

Metals Tightly Bound to Proteins Form Versatile Electron Carriers 425(2)

Protons Are Pumped Across the Membrane by the Three Respiratory Enzyme Complexes 427(2)

Respiration Is Amazingly Efficient 429(1)

Chloroplasts and Photosynthesis 430(9)

Chloroplasts Resemble Mitochondria but Have an Extra Compartment 430(2)

Chloroplasts Capture Energy from Sunlight and Use It to Fix Carbon 432(1)

Excited Chlorophyll Molecules Funnel Energy into a Reaction Center 433(1)

Light Energy Drives the Synthesis of ATP and NADPH 434(2)

Carbon Fixation Is Catalyzed by Ribulose Bisphosphate Carboxylase 436(2)

Carbon Fixation in Chloroplasts Generates Sucrose and Starch 438(1)

The Genetic Systems of Mitochondria and Chloroplasts Reflect Their Procaryotic Origin 438(1)

Our Single-celled Ancestors 439(4)

RNA Sequences Reveal Evolutionary History 439(1)

Ancient Cells Probably Arose in Hot Environments 440(1)

Methanococcus Lives in the Dark, Using Only Inorganic Materials as Food 441(2)

Essential Concepts 443(1)

Questions 444(4)

Chapter 14 Intracellular Compartments and Transport 448(34)

Membrane-bounded Organelles 448(4)

Eucaryotic Cells Contain a Basic Set of Membrane-bounded Organelles 449(1)

Membrane-bounded Organelles Evolved in Different Ways 450(2)

Protein Sorting 452(10)

Proteins Are Imported into Organelles by Three Mechanisms 453(1)

Signal Sequences Direct Proteins to the Correct Compartment 453(2)

Proteins Enter the Nucleus Through Nuclear Pores 455(2)

Proteins Unfold to Enter Mitochondria and Chloroplasts 457(1)

Proteins Enter the Endoplasmic Reticulum While Being Synthesized 458(1)

Soluble Proteins Are Released into the ER Lumen 459(2)

Start and Stop Signals Determine the Arrangement of a Transmembrane Protein in the Lipid Bilayer 461(1)

Vesicular Transport 462(5)

Transport Vesicles Carry Soluble Proteins and Membrane Between Compartments 463(1)

Vesicle Budding Is Driven by the Assembly of a Protein Coat 463(2)

The Specificity of Vesicle Docking Depends on SNAREs 465(2)

Secretory Pathways 467(5)

Most Proteins Are Covalently Modified in the ER 467(1)

Exit from the ER Is Controlled to Ensure Protein Quality 468(1)

Proteins Are Further Modified and Sorted in the Golgi Apparatus 469(1)

Secretory Proteins Are Released from the Cell by Exocytosis 470(2)

Endocytic Pathways 472(6)

Specialized Phagocytic Cells Ingest Large Particles 472(1)

Fluid and Macromolecules Are Taken Up by Pinocytosis 473(1)

Receptor-mediated Endocytosis Provides a Specific Route into Animal Cells 474(1)

Endocytosed Macromolecules Are Sorted in Endosomes 475(1)

Lysosomes Are the Principal Sites of Intracellular Digestion 476(2)

Essential Concepts 478(1)

Questions 479(3)

Chapter 15 Cell Communication 482(32)

General Principles of Cell Signaling 482(11)

Signals Can Act over Long or Short Range 482(2)

Each Cell Responds to a Limited Set of Signals 484(2)

Receptors Relay Signals via Intracellular Signaling Pathways 486(2)

Some Signal Molecules Can Cross the Plasma Membrane 488(1)

Nitric Oxide Can Enter Cells to Activate Enzymes Directly 489(1)

There Are Three Main Classes of Cell-Surface Receptors 490(1)

Ion-Channel-linked Receptors Convert Chemical Signals into Electrical Ones 491(1)

Intracellular Signaling Cascades Act as a Series of Molecular Switches 492(1)

G-Protein-linked Receptors 493(11)

Stimulation of G-Protein-linked Receptors Activates G-Protein Subunits 493(2)

Some G Proteins Regulate Ion Channels 495(1)

Some G Proteins Activate Membrane-bound Enzymes 496(1)

The Cyclic AMP Pathway Can Activate Enzymes and Turn On Genes 497(2)

The Pathway Through Phospholipase C Results in a Rise in Intracellular Ca(2+) 499(2)

A Ca(2+) Signal Triggers Many Biological Processes 501(1)

Intracellular Signaling Cascades Can Achieve Astonishing Speed, Sensitivity, and Adaptability: Photoreceptors in the Eye 502(2)

Enzyme-linked Receptors 504(6)

Activated Receptor Tyrosine Kinases Assemble a Complex of Intracellular Signaling Proteins 505(1)

Receptor Tyrosine Kinases Activate the GTP-binding Protein Ras 506(2)

Protein Kinase Networks Integrate Information to Control Complex Cell Behaviors 508(2)

Essential Concepts 510(1)

Questions 511(3)

Chapter 16 Cytoskeleton 514(35)

Intermediate Filaments 514(4)

Intermediate Filaments Are Strong and Durable 515(1)

Intermediate Filaments Strengthen Cells Against Mechanical Stress 516(2)

Microtubules 518(11)

Microtubules Are Hollow Tubes with Structurally Distinct Ends 519(1)

Microtubules Are Maintained by a Balance of Assembly and Disassembly 519(2)

The Centrosome Is the Major Microtubule-organizing Center in Animal Cells 521(1)

Growing Microtubules Show Dynamic Instability 522(1)

Microtubules Organize the Interior of the Cell 523(2)

Motor Proteins Drive Intracellular Transport 525(1)

Organelles Move Along Microtubules 526(1)

Cilia and Flagella Contain Stable Microtubules Moved by Dynein 527(2)

Actin Filaments 529(14)

Actin Filaments Are Thin and Flexible 530(1)

Actin and Tubulin Polymerize by Similar Mechanisms 531(1)

Many Proteins Bind to Actin and Modify Its Properties 532(1)

Actin-rich Cortex Underlines the Plasma Membrane of Most Eucaryotic Cells 533(1)

Cell Crawling Depends on Actin 533(3)

Actin Associates with Myosin to Form Contractile Structures 536(2)

During Muscle Contraction Actin Filaments Slide Against Myosin Filaments 538(1)

Muscle Contraction Is Triggered by a Sudden Rise in Ca(2+) 539(4)

Essential Concepts 543(1)

Questions 544(5)

Chapter 17 Cell Division 549(23)

Overview of the Cell Cycle 549(3)

The Eucaryotic Cell Cycle Is Divided into Four Phases 549(2)

The Cytoskeleton Carries Out Both Mitosis and Cytokinesis 551(1)

Some Organelles Fragment at Mitosis 551(1)

Mitosis 552(8)

The Mitotic Spindle Starts to Assemble in Prophase 552(1)

Chromosomes Attach to the Mitotic Spindle at Prometaphase 553(4)

Chromosomes Line Up at the Spindle Equator at Metaphase 557(1)

Daughter Chromosomes Segregate at Anaphase 557(2)

The Nuclear Envelope Re-forms at Telophase 559(1)

Cytokinesis 560(3)

The Mitotic Spindle Determines the Plane of Cytoplasmic Cleavage 560(1)

The Contractile Ring of Animal Cells Is Made of Actin and Myosin 561(1)

Cytokinesis in Plant Cells Involves New Cell-Wall Formation 562(1)

Meiosis 563(4)

Homologous Chromosomes Pair Off During Meiosis 563(1)

Meiosis Involves Two Cell Divisions Rather Than One 564(3)

Essential Concepts 567(1)

Questions 568(4)

Chapter 18 Cell-Cycle Control and Cell Death 572(22)

The Cell-Cycle Control System 572(10)

A Central Control System Triggers the Major Processes of the Cell Cycle 572(2)

The Cell-Cycle Control System Is Based on Cyclically Activated Protein Kinases 574(1)

MPF Is the Cyclin-Cdk Complex That Controls Entry into M Phase 575(1)

Cyclin-dependent Protein Kinases Are Regulated by the Accumulation and Destruction of Cyclin 576(2)

The Activity of Cdks Is Further Regulated by Their Phosphorylation and Dephosphorylation 578(1)

Different Cyclin-Cdk Complexes Trigger Different Steps in the Cell Cycle 578(2)

The Cell Cycle Can Be Halted in G(1) by Cdk Inhibitor Proteins 580(1)

Cells Can Dismantle Their Control System and Withdraw from the Cell Cycle 581(1)

Control of Cell Numbers in Multicellular Organisms 582(7)

Cell Proliferation Depends on Signals from Other Cells 582(2)

Animal Cells Have a Built-in Limitation on the Number of Times They Will Divide 584(1)

Animal Cells Require Signals from Other Cells to Avoid Programmed Cell Death 584(1)

Programmed Cell Death Is Mediated by an Intracellular Proteolytic Cascade 585(2)

Cancer Cells Disobey the Social Controls on Cell Proliferation and Survival 587(2)

Essential Concepts 589(1)

Questions 590(4)

Chapter 19 Tissues 594

Extracellular Matrix and Connective Tissues 594(11)

Plant Cells Have Tough External Walls 594(2)

Cellulose Fibers Give the Plant Cell Wall Its Tensile Strength 596(4)

Animal Connective Tissues Consist Largely of Extracellular Matrix 600(1)

Collagen Provides Tensile Strength in Animal Connective Tissues 600(2)

Cells Organize the Collagen That They Secrete 602(1)

Integrins Couple the Matrix Outside a Cell to the Cytoskeleton Inside It 603(1)

Gels of Polysaccharide and Protein Fill Spaces and Resist Compression 604(1)

Epithelial Sheets and Cell-Cell Junctions 605(8)

Epithelial Sheets Are Polarized and Rest on a Basal Lamina 606(1)

Tight Junctions Make an Epithelium Leak-proof and Separate Its Apical and Basal Surfaces 607(2)

Cytoskeleton-linked Junctions Bind Epithelial Cells Robustly to One Another and to the Basal Lamina 609(3)

Gap Junctions Allow Ions and Small Molecules to Pass from Cell to Cell 612(1)

Tissue Maintenance and Renewal, and Its Disruption by Cancer 613(8)

Different Tissues Are Renewed at Different Rates 615(1)

Stem Cells Generate a Continuous Supply of Terminally Differentiated Cells 615(3)

Mutations in a Single Dividing Cell Can Cause It and Its Progeny to Violate the Normal Controls 618(1)

Cancer Is a Consequence of Mutation and Natural Selection Within the Population of Cells That Form the Body 619(1)

Cancer Requires an Accumulation of Mutations 620(1)

Development 621(7)

Programmed Cell Movements Create the Animal Body Plan 622(1)

Cells Switch On Different Sets of Genes According to Their Position and Their History 622(2)

Diffusible Signals Can Provide Cells with Positional Information 624(2)

Studies in Drosophila Have Given a Key to Vertebrate Development 626(1)

Similar Genes Are Used Throughout the Animal Kingdom to Give Cells an Internal Record of Their Position 627(1)

Essential Concepts 628(1)

Questions 629