Life : the science of biology / [edited by] David Sadava .. [et al.].

Includes index.

PART ONE. THE SCIENCE OF LIFE AND ITS CHEMICAL BASIS -- 1. Studying Life -- 1.1. What is Biology? -- Cells are the basic unit of life -- All of life shares a common evolutionary history -- Biological information is contained in a genetic language common to all organisms -- Cells use nutrients to supply energy and to build new structures -- Living organisms regulate their internal environment -- Living organisms interact with one another -- Discoveries in biology can be generalized -- 1.2. How is All Life on Earth Related? -- Life arose from non-life via chemical evolution -- Cellular structure evolved in the common ancestor of life -- Photosynthesis changed the course of evolution -- Eukaryotic cells evolved from prokaryotes -- Multicellularity arose and cells became specialized -- Biologists can trace the evolutionary tree of life -- The tree of life is predictive -- 1.3. How Do Biologists Investigate Life? -- Observation is an important skill -- The scientific method combines observation and logic -- Good experiments have the potential to falsify hypotheses -- Statistical methods are essential scientific tools -- Not all forms of inquiry are scientific -- 1.4. How Does Biology Influence Public Policy? -- 2. Small Molecules and the Chemistry of Life -- 2.1. How Does Atomic Structure Explain the Properties of Matter? -- An element consists of only one kind of atom -- Each element has a different number of protons -- The number of neutrons differs among isotopes -- The behavior of electrons determines chemical bonding and geometry -- 2.2. How Do Atoms Bond to Form Molecules? -- Covalent bonds consist of shared pairs of electrons -- Ionic bonds form by electrical attraction -- Hydrogen bonds may form within or between molecules with polar covalent bonds -- Polar and nonpolar substances: Each interacts best with its own kind -- 2.3. How Do Atoms Change Partners in Chemical Reactions? -- 2.4. What Makes Water So Important for Life? -- Water has a unique structure and special properties -- Water is an excellent solvent---the medium of life -- Aqueous solutions may be acidic or basic -- An Overview and a Preview -- 3. Proteins, Carbohydrates, and Lipids -- 3.1. What Kinds of Molecules Characterize Living Things? -- Functional groups give specific properties to biological molecules -- Isomers have different arrangements of the same atoms -- The structures of macromolecules reflect their functions -- Most macromolecules are formed by condensation and broken down by hydrolysis -- 3.2. What Are the Chemical Structures and Functions of Proteins? -- Amino acids are the building blocks of proteins -- Peptide linkages from the backbone of a protein -- The primary structure of a protein is its amino acid sequence -- The secondary structure of a protein requires hydrogen bonding -- The tertiary structure of a protein is formed by bending and folding -- The quaternary structure of a protein consists of subunits -- Shape and surface chemistry contribute to protein function -- Environmental conditions affect protein structure -- Molecular chaperones help shape proteins -- 3.3. What Are the Chemical Structures and Functions of Carbohydrates? -- Monosaccharides are simple sugars -- Glycosidic linkages bond monosaccharides -- Polysaccharides store energy and provide structural materials -- Chemically modified carbohydrates contain additional functional groups -- 3.4. What Are the Chemical Structures and Functions of Lipids? -- Fats and oils are hydrophobic -- Phospholipids form biological membranes -- Lipids have roles in energy conversion, regulation, and protection -- 4. Nucleic Acids and the Origin of Life -- 4.1. What Are the Chemical Structures and Functions of Nucleic Acids? -- Nucleotides are the building blocks of nucleic acids -- Base pairing occurs in both DNA and RNA -- DNA carries information and is expressed through RNA -- The DNA base sequence reveals evolutionary relationships -- Nucleotides have other important roles -- 4.2. How and Where Did the Small Molecules of Life Originate? -- Experiments disproved spontaneous generation of life -- Life began in water -- Life may have come from outside Earth -- Prebiotic synthesis experiments model the early Earth -- 4.3. How Did the Large Molecules of Life Originate? -- Chemical evolution may have led to polymerization -- There are two theories for the emergence of nucleic acids, proteins, and complex chemistry -- RNA may have been the first biological catalyst -- 4.4. How Did the First Cells Originate? -- Experiments describe the origin of cells -- Some ancient cells left a fossil imprint -- Part TWO. CELLS -- 5. Cells: The Working Units of Life -- 5.1. What Features Make Cells the Fundamental Units of Life? -- Cell size is limited by the surface area-to-volume ratio -- Microscopes reveal the features of cells -- The plasma membrane forms the outer surface of every cell -- All cells are classified as either prokaryotic or eukaryotic -- 5.2. What Features Characterize Prokaryotic Cells? -- Prokaryotic cells share certain features -- Specialized features are found in some prokaryotes -- 5.3. What Features Characterize Eukaryotic Cells? -- Compartmentalization is the key to eukaryotic cell function -- Organelles can be studied by microscopy or isolated for chemical analysis -- Ribosomes are factories for protein synthesis -- The nucleus contains most of the genetic information -- The endomembrane system is a group of interrelated organelles -- Some organelles transform energy -- There are several other membrane-enclosed organelles -- The cytoskeleton is important in cell structure and movement -- 5.4. What Are the Roles of Extracellular Structures? -- The plant cell wall is an extracellular structure -- The extracellular matrix supports tissue functions in animals -- 5.5. How Did Eukaryotic Cells Originate? -- Internal membranes and the nuclear envelope probably came from the plasma membrane -- Some organelles arose by endosymbiosis -- 6. Cell Membranes -- 6.1. What is the Structure of a Biological Membrane? -- Lipids form the hydrophobic core of the membrane -- Membrane proteins are asymmetrically distributed -- Membranes are constantly changing -- Plasma membrane carbohydrates are recognition sites -- 6.2. How is the Plasma Membrane Involved in Cell Adhesion and Recognition? -- Cell recognition and cell adhesion involve proteins at the cell surface -- Three types of cell junctions connect adjacent cells -- Cell membranes adhere to the extracellular matrix -- 6.3. What Are the Passive Processes of Membrane Transport? -- Diffusion is the process of random movement toward a state of equilibrium -- Simple diffusion takes place through the phospholipid bilayer -- Osmosis is the diffusion of water across membranes -- Diffusion may be aided by channel proteins -- Carrier proteins aid diffusion by binding substances -- 6.4. What are the Active Processes of Membrane Transport? -- Active transport is directional -- Different energy sources distinguish different active transport systems -- 6.5. How Do Large Molecules Enter and Leave a Cell? -- Macromolecules and particles enter the cell by endocytosis -- Receptor-mediated endocytosis is highly specific -- Exocytosis moves materials out of the cell -- 6.6. What Are Some Other Functions of Membranes? -- 7. Cell Signaling and Communication -- 7.1. What Are Signals, and How Do Cells Respond to Them? -- Cells receive signals from the physical environment and from other cells -- A signal transduction pathway involves a signal, a receptor, and responses -- 7.2. How Do Signal Receptors Initiate a Cellular Response? -- Receptors have specific binding sites for their signals -- Receptors can be classified by location and function -- 7.3. How is the Response to a Signal Transduced through the Cell? --

A protein kinase cascade amplifies a response to ligand binding -- Second messengers can stimulate protein kinase cascades -- Second messengers can be derived from lipids -- Calcium ions are involved in many signal transduction pathways -- Nitric oxide can act in signal transduction -- Signal transduction is highly regulated -- 7.4. How Do Cells Change in Response to Signals? -- Ion channels open in response to signals -- Enzyme activities change in response to signals -- Signals can initiate DNA transcription -- 7.5. How Do Cells Communicate Directly? -- Animal cells communicate by gap junctions -- Plant cells communicate by plasmodesmata -- PART THREE. CELLS AND ENERGY -- 8. Energy, Enzymes, and Metabolism -- 8.1. What Physical Principles Underlie Biological Energy Transformations? -- There are two basic types of energy and of metabolism -- The first law of thermodynamics: Energy is neither created nor destroyed -- The second law of thermodynamics: Disorder tends to increase -- Chemical reactions release or consume energy -- Chemical equilibrium and free energy are related -- 8.2. What is the Role of ATP in Biochemical Energetics? -- ATP hydrolysis releases energy -- ATP couples exergonic and endergonic reactions -- 8.3. What Are Enzymes? -- To speed up a reaction, an energy barrier must be overcome -- Enzymes bind specific reactants at their active sites -- Enzymes lower the energy barrier but do not affect equilibrium -- 8.4. How Do Enzymes Work? -- Enzymes can orient substrates -- Enzymes can induce strain in the substrate -- Enzymes can temporarily add chemical groups to substrates -- Molecular structure determines enzyme function -- Some enzymes require other molecules in order to function -- The substrate concentration affects the reaction rate -- 8.5. How Are Enzyme Activities Regulated? -- Enzymes can be regulated by inhibitors -- Allosteric enzymes control their activity by changing shape -- Allosteric effects regulate metabolism -- Enzymes are affected by their environment -- 9. Pathways that Harvest Chemical Energy -- 9.1. How Does Glucose Oxidation Release Chemical Energy? -- Cells trap free energy while metabolizing glucose -- Redox reactions transfer electrons and energy -- The coenzyme NAD+ is a key electron carrier in redox reactions -- An overview: Harvesting energy from glucose -- 9.2. What Are the Aerobic Pathways of Glucose Metabolism? -- The energy-investing reactions 1-5 of glycolysis require ATP -- The energy-harvesting reactions 6-10 of glycolysis yield NADH and ATP -- Pyruvate oxidation links glycolysis and the citric acid cycle -- The citric acid cycle completes the oxidation of glucose to CO2 -- The citric acid cycle is regulated by the concentrations of starting materials -- 9.3. How Does Oxidative Phosphorylation Form ATP? -- The respiratory chain transfers electrons and releases energy -- Proton diffusion is coupled to ATP synthesis -- 9.4. How is Energy Harvested from Glucose in the Absence of Oxygen? -- Cellular respiration yields much more energy than fermentation -- The yield of ATP is reduced by the impermeability of some mitochondria to NADH -- 9.5. How are Metabolic Pathways Interrelated and Regulated? -- Catabolism and anabolism are linked -- Catabolism and anabolism are integrated -- Metabolic pathways are regulated systems -- 10. Photosynthesis: Energy from Sunlight -- 10.1. What Is Photosynthesis? -- Experiments with isotopes show that in photosynthesis O2 comes from H2O -- Photosynthesis involves two pathways -- 10.2. How Does Photosynthesis Convert Light Energy into Chemical Energy? -- Light is a form of energy with dual properties -- Molecules become excited when they absorb photons -- Absorbed wavelengths correlate with biological activity -- Several pigments absorb energy for photosynthesis -- Light absorption results in photochemical change -- Excited chlorophylls in the reaction center act as electron donors -- Reduction leads to electron transport -- Noncyclic electron transport produces ATPand NADPH -- Cyclic electron transport produces ATP but no NADPH -- Chemiosmosis is the source of the ATP produced in photophosphorylation -- 10.3. How is Chemical Energy Used to Synthesize Carbohydrates? -- Radioisotope labeling experiments revealed the steps of the Calvin cycle -- The Calvin cycle is made up of three processes -- Light stimulates the Calvin cycle -- 10.4. How Do Plants Adapt to the Inefficiencies of Photosynthesis? -- Rubisco catalyzes the reaction of RuBP with O2 or CO2 -- C3 plants undergo photorespiration but C4 plants do not -- CAM plants also use PEP carboxylase -- 10.5. How Does Photosynthesis Interact with Other Pathways? -- PART FOUR. GENES AND HEREDITY -- 11. The Cell Cycle and Cell Division -- 11.1. How Do Prokaryotic and Eukaryotic Cells Divide? -- Prokaryotes divide by binary fission -- Eukaryotic cells divide by mitosis or meiosis followed by cytokinesis -- 11.2. How is Eukaryotic Cell Division Controlled? -- Specific signals trigger events in the cell cycle -- Growth factors can stimulate cells to divide -- 11.3. What Happens during Mitosis? -- Prior to mitosis, eukaryotic DNA is packed into very compact chromosomes -- Overview: Mitosis segregates copies of genetic information -- The centrosomes determine the plane of cell division -- The spindle begins to form during prophase -- Chromosome separation and movement are highly organized -- Cytokinesis is the division of the cytoplasm -- 11.4. What Role Does Cell Division Play in a Sexual Life Cycle? -- Asexual reproduction by mitosis results in genetic constancy -- Sexual reproduction by meiosis results in genetic diversity -- The number, shapes, and sizes of the metaphase chromosomes constitute the karyotype -- 11.5. What Happens during Meiosis? -- Meiotic division reduces the chromosome number -- Chromatid exchanges during meiosis I generate genetic diversity -- During meiosis homologous chromosomes separate by independent assortment -- Meiotic errors lead to abnormal chromosome structures and numbers -- Polyploids have more than two complete sets of chromosomes -- 11.6. In a Living Organism, How Do Cells Die? -- 11.7. How Does Unregulated Cell Division Lead to Cancer? -- Cancer cells differ from normal cells -- Cancer cells lose control over the cell cycle and apoptosis -- Cancer treatments target the cell cycle -- 12. Inheritance, Genes, and Chromosomes -- 12.1. What Are the Mendelian Laws of Inheritance? -- Mendel brought new methods to experiments on inheritance -- Mendel devised a careful research plan -- Mendel's first experiments involved monohybrid crosses -- Alleles are different forms of a gene -- Mendel's first law says that the two copies of a gene segregate -- Mendel verified his hypothesis by performing a test cross -- Mendel's second law says that copies of different genes assort independently -- Punnett squares or probability calculations: A choice of methods -- Mendel's laws can be observed in human pedigrees -- 12.2. How Do Alleles Interact? -- New alleles arise by mutation -- Many genes have multiple alleles -- Dominance is not always complete -- In codominance, both alleles at a locus are expressed -- Some alleles have multiple phenotypic effects -- 12.3. How Do Genes Interact? -- Hybrid vigor results from new gene combinations and interactions -- The environment affects gene action -- Most complex phenotypes are determined by multiple genes and the environment -- 12.4. What is the Relationship between Genes and Chromosomes? -- Genes on the same chromosome are linked -- Genes can be exchanged between chromatids -- Geneticists can make maps of chromosomes -- Linkage is revealed by studies of the sex chromosomes -- Genes on sex chromosomes are inherited in special ways -- Humans display many sex-linked characters -- 12.5. What Are the Effects of Genes Outside the Nucleus? --

12.6. How Do Prokaryotes Transmit Genes? -- Bacteria exchange genes by conjugation -- Plasmids transfer genes between bacteria -- 13. DNA and Its Role in Heredity -- 13.1. What is the Evidence that the Gene is DNA? -- DNA from one type of bacterium genetically transforms another type -- The transforming principle is DNA -- Viral replication experiments confirmed that DNA is the genetic material -- Eukaryotic cells can also be genetically transformed by DNA -- 13.2. What is the Structure of DNA? -- The chemical composition of DNA was known -- Watson and Crick described the double helix -- Four key features define DNA structure -- The double-helical structure of DNA is essential to its function -- 13.3. How is DNA Replicated? -- Three modes of DNA replication appeared possible -- An elegant experiment demonstrated that DNA replication is semiconservative -- There are two steps in DNA replication -- DNA polymerases add nucleotides to the growing chain -- Many other proteins assist with DNA polymerization -- Telomeres are not fully replicated and are prone to repair -- 13.4. How Are Errors in DNA Repaired? -- 13.5. How Does the Polymerase Chain Reaction Amplify DNA? -- The polymerase chain reaction makes multiple copies of DNA sequences -- 14. From DNA to Protein: Gene Expression -- 14.1. What is the Evidence that Genes Code for Proteins? -- Observations in humans led to the proposal that genes determine enzymes -- Experiments on bread mold established that genes determine enzymes -- One gene determines one polypeptide -- 14.2. How Does Information Flow from Genes to Proteins? -- RNA differs from DNA and plays a vital role in gene expression -- Two hypotheses were proposed to explain information flow from DNA to protein -- RNA viruses are exceptions to the central dogma -- 14.3. How is the Information Content in DNA Transcribed to Produce RNA? -- RNA polymerases share common features -- Transcription occurs in three steps -- The information for protein synthesis lies in the genetic code -- 14.4. How is Eukaryotic DNA Transcribed and the RNA Processed? -- Eukaryotic genes have noncoding sequences -- Eukaryotic gene transcripts are processed before translation -- 14.5. How is RNA Translated into Proteins? -- Transfer RNAs carry specific amino acids and bind to specific codons -- Activating enzymes link the right tRNAs and amino acids -- The ribosome is the workbench for translation -- Translation takes place in three steps -- Polysome formation increases the rate of protein synthesis -- 14.6. What Happens to Polypeptides after Translation? -- Signal sequences in proteins direct them to their cellular destinations.