Organic Chemistry

Organic Chemistry • Introduction to organic chemistry • Principles of carbon chemistry • Principle of polymers • Hydrocarbons • Organic chemistry and biochemistry • Take Home Message

Elements of the Solar System: Importance of Carbon • 25 of 92 natural elements are known to be essential to life on Earth • Four of the above make up 96%! • Carbon (C), Oxygen (O), Hydrogen (H) and Nitrogen (N) • Compare to solar abundance and discuss relative to evolution of biochemistry in origin of life

Elements of the Periodic Table

Frequency of Carbon • Carbon as a building block • C is the 4th most common element in the solar system • Probably the same frequency elsewhere in the Universe • Conclusion: C is common throughout the Universe and is likely to behave similarly (C and its tendency to form covalent bonds) in most environments

Chemistry Subdivisions • Organic Chemistry • Chemistry of compounds in which C is the principal element (biotic/living and abiotic/non-living) • Inorganic Chemistry • Chemistry of all other elements • Significance of C in chemistry

Principles of Carbon Chemistry: C’s Atom • C is unparalleled in its ability to form molecules that are large, complex and diverse in structure • Key is the C atom (protons, electrons, and quantum mechanics) • C has ____ electrons • Little tendency to gain or loose electrons (i.e., no ionic bonding) • Greater likelihood for electrons to be shared in covalent bonds • Possible covalent bonds per atom from __ to ___ • Most common elements with which C bonds • O, H, N and C (compare with prominence in living systems)

Principles of Carbon Chemistry: Linkages among Carbon Atoms • Linkages among C atoms form macromolecules (define) • Chains of C (methane and ethane) • Branches of C • Rings of C (e.g., benzene)

Principles of Carbon Chemistry: Functional Groups • Distinctive features of C macromolecules is a function of two aspects of the molecules • Carbon skeleton (chains, branches, rings) • Chains, branches or rings • Number of C atoms (2, 3, 4, etc.) • Groups of atoms attached to carbon skeleton • Called functional groups (some example) • Hydroxyl (OH) • Amino (NH2) • Phosphate (P) • Total of five different functional groups

Organic Chemistry • Introduction to organic chemistry • Principles of carbon chemistry • Principle of polymers • Hydrocarbons • Organic chemistry and biochemistry • Take Home message

Principle of Polymers: Introduction • Principle of hierarchy theory and emergent properties • Small molecules joined together to form large molecules up to 1,000’s of C atoms • Macromolecules • Infinite array of possible combinations, each with its own unique chemistry

Principle of Polymers • In living systems, polymers of C results in four major classes of compounds that are of extreme importance • Carbohydrates • Proteins • Nucleic acids • Lipids • Linkages between C atoms via covalent bonds • Calculating potential diversity of C polymers • Analogy to alphabet (26 letters) and infinite ways to “create words” • If 45 basic different C alphabet pieces, infinite ways to create polymers of C

Organic Chemistry • Introduction to organic chemistry • Principles of carbon chemistry • Principle of polymers • Hydrocarbons • Organic chemistry and biochemistry

Hydrocarbons • Carbon compounds with only two elements: • C and H • C-C bonding via covalent bonds (nonpolar) • Number of bonds • 1, 2, 3, or 4 • Most simple compound is methane H H C H H

Hydrocarbons: C to C Bonding • C to C bond can be single bond (C-C) H H • Ethane H C-C H H H • C to C bond can be double bond (C = C) H H • Ethene C = C H H • C to C bond can be triple bond (C = C) • Ethyne H C = C H

Hydrocarbons: Groups • Alkanes • Single covalent bond between C atoms • Methane (C1H4) • Ethane (C2H6) • Propane (C3H8) • Butane (C4H10) • Pentane (C5H12) • Octane (C__H18) • Decane (C__H22) • Pattern: CnH2n+2) • Alkynes (triple bond C = C) • Alkenes (double bond or C = C) • Aromatics (rings or cyclic C atoms) • Example (C6H6)

Hydrocarbons: Saturated and Unsaturated Hydrocarbons • Saturated hydrocarbons: maximum number of H atoms bonded to C H H • Ethane or H C - C H H H • Unsaturated hydrocarbons: anything else H H • Ethylene or C = C H H

Organic Chemistry and Biochemistry • Keys: • Structure of basic unit • Polymer structure • Functional group (e.g., OH, P or NH2) • Types of C polymers for biotic systems • Carbohydrates • Lipids • Proteins • Nucleic acids

Organic Chemistry and Biochemistry: Monomers • Carbohydrates • Glucose or C6H12O6 • Functional unit: hydroxyl or OH- • Proteins • Amino acid • Functional unit: amine or NH2 • Nucleic Acids • Nucleotide or • Functional units: organic N base, carbohydrate, and phosphate • Lipids • Fatty acids C16-18 • Functional unit: glycerol (3 OH- groups)

Take Home Message • While the molecule of water is simple but exquisite and unique in its chemical behavior, the C atom is unusual and unique in its chemical behavior but for different reasons • Covalent bonding • Valence electrons • Unusual behavior of C results in extreme array of simple to very complex molecules as a function of • Polymers • Functional groups • Life as we know it is hard to imagine without C behaving as a polymer with covalent bonds to create carbohydrates, proteins, nucleic acids and lipids (C polymers) • Principle of hierarchy theory and emergent properties

Exam Coverage • Text • Chapter 9 (Atomic Structure; entire chapter) • Chapter 10 (Elements & Periodic Table; entire chapter) • Chapter 11 (Compounds and Chemical Change; entire chapter excluding pages noted in lecture and posted on the www) • Chapter 12 (Chemical Formulas; ONLY: pp 278-279; p 292 - Units of Measurement) • Chapter 13 (Water & Solutions; exclude pp 306-310 (electrolytes, boiling point, and freezing point) • Lecture Notes • Atoms and Elements; Valence Electrons and Bonding; Water; and Organic Chemistry • Labs • Physics: Electricity and Light • NO OTHER LABS FOR THIS EXAM

Help or Desperation Sessions • Tuesday @ 5:00 PM in Honors Lounge • Wednesday @ 6:30 Pm in Honors Lounge • No lecture, questions only

Organic Chemistry