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LECTURE PRESENTATIONS
                                    For CAMPBELL BIOLOGY, NINTH EDITION
                Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson



Chapter 4

Carbon and the Molecular
Diversity of Life



                                                                                                                    Lectures by
                                                                                                                    Erin Barley
                                                                                                            Kathleen Fitzpatrick

© 2011 Pearson Education, Inc.
Overview: Carbon: The Backbone of Life
     • Living organisms consist mostly of carbon-based
       compounds
     • Carbon is unparalleled in its ability to form large,
       complex, and diverse molecules
     • Proteins, DNA, carbohydrates, and other
       molecules that distinguish living matter are all
       composed of carbon compounds




© 2011 Pearson Education, Inc.
Figure 4.1
Organic chemistry is the study of carbon
compounds
     • Organic chemistry is the study of compounds
       that contain carbon
     • Organic compounds range from simple
       molecules to colossal ones
     • Most organic compounds contain hydrogen
       atoms in addition to carbon atoms




© 2011 Pearson Education, Inc.
• Vitalism, the idea that organic compounds
       arise only in organisms, was disproved when
       chemists synthesized these compounds
     • Mechanism is the view that all natural
       phenomena are governed by physical and
       chemical laws




© 2011 Pearson Education, Inc.
Organic Molecules and the Origin of Life
on Earth
     • Stanley Miller’s classic experiment
       demonstrated the abiotic synthesis of
       organic compounds
     • Experiments support the idea that abiotic
       synthesis of organic compounds, perhaps
       near volcanoes, could have been a stage in
       the origin of life




© 2011 Pearson Education, Inc.
Figure 4.2
             EXPERIMENT
                                                 “Atmosphere”
                                           CH4
                     Water vapor
                                                      Electrode

                                          NH
                                           3   H2

                                                    Condenser


                          Cooled “rain”
                          containing                      Cold
                          organic                         water
                          molecules




                      H2O
                      “sea”


                   Sample for chemical analysis
Carbon atoms can form diverse molecules by
bonding to four other atoms
     • Electron configuration is the key to an atom’s
       characteristics
     • Electron configuration determines the kinds
       and number of bonds an atom will form with
       other atoms




© 2011 Pearson Education, Inc.
The Formation of Bonds with Carbon
     • With four valence electrons, carbon can form
       four covalent bonds with a variety of atoms
     • This ability makes large, complex molecules
       possible
     • In molecules with multiple carbons, each carbon
       bonded to four other atoms has a tetrahedral
       shape
     • However, when two carbon atoms are joined by
       a double bond, the atoms joined to the carbons
       are in the same plane as the carbons


© 2011 Pearson Education, Inc.
Figure 4.3


    Name and       Molecular   Structural    Ball-and-    Space-Filling
    Comment        Formula      Formula     Stick Model      Model
  (a) Methane

                     CH4




  (b) Ethane

                     C2H6




  (c) Ethene
      (ethylene)
                     C2H4
• The electron configuration of carbon gives it
       covalent compatibility with many different
       elements
     • The valences of carbon and its most frequent
       partners (hydrogen, oxygen, and nitrogen) are
       the “building code” that governs the
       architecture of living molecules




© 2011 Pearson Education, Inc.
Figure 4.4




   Hydrogen         Oxygen         Nitrogen         Carbon
 (valence = 1)   (valence = 2)   (valence = 3)   (valence = 4)
• Carbon atoms can partner with atoms other than
       hydrogen; for example:
                – Carbon dioxide: CO2

                                 O=C=O



                – Urea: CO(NH2)2




© 2011 Pearson Education, Inc.
Figure 4.UN01




                Urea
Molecular Diversity Arising from Carbon
Skeleton Variation
     • Carbon chains form the skeletons of most
       organic molecules
     • Carbon chains vary in length and shape




© 2011 Pearson Education, Inc.
Figure 4.5




 (a) Length                         (c) Double bond position




         Ethane      Propane           1-Butene             2-Butene


 (b) Branching                      (d) Presence of rings




         Butane   2-Methylpropane       Cyclohexane            Benzene
                    (isobutane)
Hydrocarbons
     • Hydrocarbons are organic molecules
       consisting of only carbon and hydrogen
     • Many organic molecules, such as fats, have
       hydrocarbon components
     • Hydrocarbons can undergo reactions that
       release a large amount of energy




© 2011 Pearson Education, Inc.
Figure 4.6




                                        Nucleus

                                        Fat droplets




     10 µm
     (a) Part of a human adipose cell   (b) A fat molecule
Isomers
     • Isomers are compounds with the same
       molecular formula but different structures and
       properties
                – Structural isomers have different covalent
                  arrangements of their atoms
                – Cis-trans isomers have the same covalent
                  bonds but differ in spatial arrangements
                – Enantiomers are isomers that are mirror
                  images of each other



© 2011 Pearson Education, Inc.
Figure 4.7
             (a) Structural isomers




             (b) Cis-trans isomers




              cis isomer: The two Xs         trans isomer: The two Xs
              are on the same side.          are on opposite sides.


             (c) Enantiomers

                            CO2H                    CO2H




                       H               NH2   NH2              H
                            CH3                       CH3
                           L isomer                D isomer
• Enantiomers are important in the
       pharmaceutical industry
     • Two enantiomers of a drug may have different
       effects
     • Usually only one isomer is biologically active
     • Differing effects of enantiomers demonstrate
       that organisms are sensitive to even subtle
       variations in molecules



© 2011 Pearson Education, Inc.
Figure 4.8




                                Effective    Ineffective
         Drug    Condition
                               Enantiomer    Enantiomer



    Ibuprofen        Pain;
                inflammation
                               S-Ibuprofen   R-Ibuprofen



    Albuterol     Asthma

                               R-Albuterol   S-Albuterol
A few chemical groups are key to the
functioning of biological molecules
     • Distinctive properties of organic molecules
       depend on the carbon skeleton and on the
       molecular components attached to it
     • A number of characteristic groups called
       functional groups can replace the hydrogens
       attached to skeletons of organic molecules




© 2011 Pearson Education, Inc.
The Chemical Groups Most Important in
the Processes of Life
     • Functional groups are the components of
       organic molecules that are most commonly
       involved in chemical reactions
     • The number and arrangement of functional
       groups give each molecule its unique
       properties




© 2011 Pearson Education, Inc.
Figure 4.UN02




                Estradiol
                            Testosterone
• The seven functional groups that are most
       important in the chemistry of life:
                –    Hydroxyl group
                –    Carbonyl group
                –    Carboxyl group
                –    Amino group
                –    Sulfhydryl group
                –    Phosphate group
                –    Methyl group


© 2011 Pearson Education, Inc.
Figure 4.9a




                        Hydroxyl

 STRUCTURE                      Alcohols                 NAME OF
                                (Their specific          COMPOUND
                                names usually
              (may be written   end in -ol.)
                  HO—)

 EXAMPLE                        • Is polar as a result   FUNCTIONAL
                                  of the electrons       PROPERTIES
                                  spending more
                                  time near the
                                  electronegative
                                  oxygen atom.
              Ethanol           • Can form hydrogen
                                  bonds with water
                                  molecules, helping
                                  dissolve organic
                                  compounds such
                                  as sugars.
Figure 4.9b

                         Carbonyl

  STRUCTURE                 Ketones if the carbonyl       NAME OF
                            group is within a             COMPOUND
                            carbon skeleton
                            Aldehydes if the carbonyl
                            group is at the end of the
                            carbon skeleton

  EXAMPLE                  • A ketone and an              FUNCTIONAL
                             aldehyde may be              PROPERTIES
                             structural isomers
                             with different properties,
                             as is the case for
                             acetone and propanal.
                            • Ketone and aldehyde
              Acetone         groups are also found
                              in sugars, giving rise
                              to two major groups
                              of sugars: ketoses
                              (containing ketone
                              groups) and aldoses
                              (containing aldehyde
              Propanal        groups).
Figure 4.9c

                            Carboxyl

 STRUCTURE                     Carboxylic acids, or organic      NAME OF
                               acids                             COMPOUND




 EXAMPLE                       • Acts as an acid; can            FUNCTIONAL
                                 donate an H+ because the        PROPERTIES
                                 covalent bond between
                                 oxygen and hydrogen is so
                                 polar:



              Acetic acid


                               Nonionized       Ionized

                               • Found in cells in the ionized
                                 form with a charge of 1– and
                                 called a carboxylate ion.
Figure 4.9d

                        Amino

 STRUCTURE                 Amines                        NAME OF
                                                         COMPOUND




 EXAMPLE                    • Acts as a base; can        FUNCTIONAL
                                pick up an H+ from the   PROPERTIES
                                surrounding solution
                                (water, in living
                                organisms):



              Glycine

                             Nonionized       Ionized

                           • Found in cells in the
                                ionized form with a
                                charge of 1+.
Figure 4.9e

                            Sulfhydryl

 STRUCTURE                       Thiols                            NAME OF
                                                                   COMPOUND


                     (may be
                  written HS—)

 EXAMPLE                         • Two sulfhydryl groups can       FUNCTIONAL
                                   react, forming a covalent       PROPERTIES
                                   bond. This “cross-linking”
                                   helps stabilize protein
                                   structure.

                                 • Cross-linking of cysteines
                                   in hair proteins maintains
                                   the curliness or straightness
              Cysteine             of hair. Straight hair can be
                                   “permanently” curled by
                                   shaping it around curlers
                                   and then breaking and
                                   re-forming the cross-linking
                                   bonds.
Figure 4.9f



                             Phosphate

 STRUCTURE                          Organic phosphates           NAME OF
                                                                 COMPOUND




 EXAMPLE                            • Contributes negative   FUNCTIONAL
                                      charge to the molecule PROPERTIES
                                      of which it is a part
                                      (2– when at the end of
                                      a molecule, as at left;
                                      1– when located
                                      internally in a chain of
                                      phosphates).
              Glycerol phosphate    • Molecules containing
                                      phosphate groups have
                                      the potential to react
                                      with water, releasing
                                      energy.
Figure 4.9g




                                  Methyl

 STRUCTURE                           Methylated compounds           NAME OF
                                                                    COMPOUND




 EXAMPLE                             • Addition of a methyl group FUNCTIONAL
                                       to DNA, or to molecules      PROPERTIES
                                       bound to DNA, affects the
                                       expression of genes.
                                     • Arrangement of methyl
                                       groups in male and female
                                       sex hormones affects their
                                       shape and function.
              5-Methyl cytidine
ATP: An Important Source of Energy for
Cellular Processes
     • One phosphate molecule, adenosine
       triphosphate (ATP), is the primary energy-
       transferring molecule in the cell
     • ATP consists of an organic molecule called
       adenosine attached to a string of three
       phosphate groups




© 2011 Pearson Education, Inc.
Figure 4. UN04




                 Adenosine
The Chemical Elements of Life: A Review
     • The versatility of carbon makes possible the
       great diversity of organic molecules
     • Variation at the molecular level lies at the
       foundation of all biological diversity




© 2011 Pearson Education, Inc.

More Related Content

04 carbon and the molecular diversity of life

  • 1. LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson Chapter 4 Carbon and the Molecular Diversity of Life Lectures by Erin Barley Kathleen Fitzpatrick © 2011 Pearson Education, Inc.
  • 2. Overview: Carbon: The Backbone of Life • Living organisms consist mostly of carbon-based compounds • Carbon is unparalleled in its ability to form large, complex, and diverse molecules • Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds © 2011 Pearson Education, Inc.
  • 4. Organic chemistry is the study of carbon compounds • Organic chemistry is the study of compounds that contain carbon • Organic compounds range from simple molecules to colossal ones • Most organic compounds contain hydrogen atoms in addition to carbon atoms © 2011 Pearson Education, Inc.
  • 5. • Vitalism, the idea that organic compounds arise only in organisms, was disproved when chemists synthesized these compounds • Mechanism is the view that all natural phenomena are governed by physical and chemical laws © 2011 Pearson Education, Inc.
  • 6. Organic Molecules and the Origin of Life on Earth • Stanley Miller’s classic experiment demonstrated the abiotic synthesis of organic compounds • Experiments support the idea that abiotic synthesis of organic compounds, perhaps near volcanoes, could have been a stage in the origin of life © 2011 Pearson Education, Inc.
  • 7. Figure 4.2 EXPERIMENT “Atmosphere” CH4 Water vapor Electrode NH 3 H2 Condenser Cooled “rain” containing Cold organic water molecules H2O “sea” Sample for chemical analysis
  • 8. Carbon atoms can form diverse molecules by bonding to four other atoms • Electron configuration is the key to an atom’s characteristics • Electron configuration determines the kinds and number of bonds an atom will form with other atoms © 2011 Pearson Education, Inc.
  • 9. The Formation of Bonds with Carbon • With four valence electrons, carbon can form four covalent bonds with a variety of atoms • This ability makes large, complex molecules possible • In molecules with multiple carbons, each carbon bonded to four other atoms has a tetrahedral shape • However, when two carbon atoms are joined by a double bond, the atoms joined to the carbons are in the same plane as the carbons © 2011 Pearson Education, Inc.
  • 10. Figure 4.3 Name and Molecular Structural Ball-and- Space-Filling Comment Formula Formula Stick Model Model (a) Methane CH4 (b) Ethane C2H6 (c) Ethene (ethylene) C2H4
  • 11. • The electron configuration of carbon gives it covalent compatibility with many different elements • The valences of carbon and its most frequent partners (hydrogen, oxygen, and nitrogen) are the “building code” that governs the architecture of living molecules © 2011 Pearson Education, Inc.
  • 12. Figure 4.4 Hydrogen Oxygen Nitrogen Carbon (valence = 1) (valence = 2) (valence = 3) (valence = 4)
  • 13. • Carbon atoms can partner with atoms other than hydrogen; for example: – Carbon dioxide: CO2 O=C=O – Urea: CO(NH2)2 © 2011 Pearson Education, Inc.
  • 15. Molecular Diversity Arising from Carbon Skeleton Variation • Carbon chains form the skeletons of most organic molecules • Carbon chains vary in length and shape © 2011 Pearson Education, Inc.
  • 16. Figure 4.5 (a) Length (c) Double bond position Ethane Propane 1-Butene 2-Butene (b) Branching (d) Presence of rings Butane 2-Methylpropane Cyclohexane Benzene (isobutane)
  • 17. Hydrocarbons • Hydrocarbons are organic molecules consisting of only carbon and hydrogen • Many organic molecules, such as fats, have hydrocarbon components • Hydrocarbons can undergo reactions that release a large amount of energy © 2011 Pearson Education, Inc.
  • 18. Figure 4.6 Nucleus Fat droplets 10 µm (a) Part of a human adipose cell (b) A fat molecule
  • 19. Isomers • Isomers are compounds with the same molecular formula but different structures and properties – Structural isomers have different covalent arrangements of their atoms – Cis-trans isomers have the same covalent bonds but differ in spatial arrangements – Enantiomers are isomers that are mirror images of each other © 2011 Pearson Education, Inc.
  • 20. Figure 4.7 (a) Structural isomers (b) Cis-trans isomers cis isomer: The two Xs trans isomer: The two Xs are on the same side. are on opposite sides. (c) Enantiomers CO2H CO2H H NH2 NH2 H CH3 CH3 L isomer D isomer
  • 21. • Enantiomers are important in the pharmaceutical industry • Two enantiomers of a drug may have different effects • Usually only one isomer is biologically active • Differing effects of enantiomers demonstrate that organisms are sensitive to even subtle variations in molecules © 2011 Pearson Education, Inc.
  • 22. Figure 4.8 Effective Ineffective Drug Condition Enantiomer Enantiomer Ibuprofen Pain; inflammation S-Ibuprofen R-Ibuprofen Albuterol Asthma R-Albuterol S-Albuterol
  • 23. A few chemical groups are key to the functioning of biological molecules • Distinctive properties of organic molecules depend on the carbon skeleton and on the molecular components attached to it • A number of characteristic groups called functional groups can replace the hydrogens attached to skeletons of organic molecules © 2011 Pearson Education, Inc.
  • 24. The Chemical Groups Most Important in the Processes of Life • Functional groups are the components of organic molecules that are most commonly involved in chemical reactions • The number and arrangement of functional groups give each molecule its unique properties © 2011 Pearson Education, Inc.
  • 25. Figure 4.UN02 Estradiol Testosterone
  • 26. • The seven functional groups that are most important in the chemistry of life: – Hydroxyl group – Carbonyl group – Carboxyl group – Amino group – Sulfhydryl group – Phosphate group – Methyl group © 2011 Pearson Education, Inc.
  • 27. Figure 4.9a Hydroxyl STRUCTURE Alcohols NAME OF (Their specific COMPOUND names usually (may be written end in -ol.) HO—) EXAMPLE • Is polar as a result FUNCTIONAL of the electrons PROPERTIES spending more time near the electronegative oxygen atom. Ethanol • Can form hydrogen bonds with water molecules, helping dissolve organic compounds such as sugars.
  • 28. Figure 4.9b Carbonyl STRUCTURE Ketones if the carbonyl NAME OF group is within a COMPOUND carbon skeleton Aldehydes if the carbonyl group is at the end of the carbon skeleton EXAMPLE • A ketone and an FUNCTIONAL aldehyde may be PROPERTIES structural isomers with different properties, as is the case for acetone and propanal. • Ketone and aldehyde Acetone groups are also found in sugars, giving rise to two major groups of sugars: ketoses (containing ketone groups) and aldoses (containing aldehyde Propanal groups).
  • 29. Figure 4.9c Carboxyl STRUCTURE Carboxylic acids, or organic NAME OF acids COMPOUND EXAMPLE • Acts as an acid; can FUNCTIONAL donate an H+ because the PROPERTIES covalent bond between oxygen and hydrogen is so polar: Acetic acid Nonionized Ionized • Found in cells in the ionized form with a charge of 1– and called a carboxylate ion.
  • 30. Figure 4.9d Amino STRUCTURE Amines NAME OF COMPOUND EXAMPLE • Acts as a base; can FUNCTIONAL pick up an H+ from the PROPERTIES surrounding solution (water, in living organisms): Glycine Nonionized Ionized • Found in cells in the ionized form with a charge of 1+.
  • 31. Figure 4.9e Sulfhydryl STRUCTURE Thiols NAME OF COMPOUND (may be written HS—) EXAMPLE • Two sulfhydryl groups can FUNCTIONAL react, forming a covalent PROPERTIES bond. This “cross-linking” helps stabilize protein structure. • Cross-linking of cysteines in hair proteins maintains the curliness or straightness Cysteine of hair. Straight hair can be “permanently” curled by shaping it around curlers and then breaking and re-forming the cross-linking bonds.
  • 32. Figure 4.9f Phosphate STRUCTURE Organic phosphates NAME OF COMPOUND EXAMPLE • Contributes negative FUNCTIONAL charge to the molecule PROPERTIES of which it is a part (2– when at the end of a molecule, as at left; 1– when located internally in a chain of phosphates). Glycerol phosphate • Molecules containing phosphate groups have the potential to react with water, releasing energy.
  • 33. Figure 4.9g Methyl STRUCTURE Methylated compounds NAME OF COMPOUND EXAMPLE • Addition of a methyl group FUNCTIONAL to DNA, or to molecules PROPERTIES bound to DNA, affects the expression of genes. • Arrangement of methyl groups in male and female sex hormones affects their shape and function. 5-Methyl cytidine
  • 34. ATP: An Important Source of Energy for Cellular Processes • One phosphate molecule, adenosine triphosphate (ATP), is the primary energy- transferring molecule in the cell • ATP consists of an organic molecule called adenosine attached to a string of three phosphate groups © 2011 Pearson Education, Inc.
  • 35. Figure 4. UN04 Adenosine
  • 36. The Chemical Elements of Life: A Review • The versatility of carbon makes possible the great diversity of organic molecules • Variation at the molecular level lies at the foundation of all biological diversity © 2011 Pearson Education, Inc.

Editor's Notes

  1. Figure 4.1 What properties make carbon the basis of all life?
  2. Figure 4.2 Inquiry: Can organic molecules form under conditions believed to simulate those on the early Earth?
  3. Figure 4.3 The shapes of three simple organic molecules.
  4. Figure 4.4 Valences of the major elements of organic molecules.
  5. Figure 4.UN01 In-text figure, p. 61
  6. Figure 4.5 Four ways that carbon skeletons can vary.
  7. Figure 4.6 The role of hydrocarbons in fats.
  8. Figure 4.7 Three types of isomers, compounds with the same molecular formula but different structures.
  9. Figure 4.8 The pharmacological importance of enantiomers.
  10. Figure 4.UN02 In-text figure, p. 63
  11. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  12. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  13. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  14. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  15. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  16. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  17. Figure 4.9 Exploring: Some Biologically Important Chemical Groups
  18. Figure 4.UN04 In-text figure, p. 66