Organic Chemistry
• Introduction to organic chemistry
• Principles of carbon chemistry
• Principle of polymers
• Hydrocarbons
• Organic chemistry and biochemistry
• Take Home Message
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
Relative Abundance of Elements in the Sun
0
2
4
6
8
10
12
0 5 10 15 20 25 30 35 40 45
Atomic Number
Lo
g o
f R
ela
tiv
e
Ab
un
dan
ce (
Si)
H
He
Li
Be B
C
C
N
O
Fe
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Fe
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
Organic Chemistry
• Introduction to organic chemistry
• Principles of carbon chemistry
• Principle of polymers
• Hydrocarbons
• Organic chemistry and biochemistry
• Take Home Message
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
HH 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 = CH 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
• Introduction to organic chemistry
• Principles of carbon chemistry
• Principle of polymers
• Hydrocarbons
• Organic chemistry and biochemistry
• Take Home Message
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)
Organic Chemistry
• Introduction to organic chemistry
• Principles of carbon chemistry
• Principle of polymers
• Hydrocarbons
• Organic chemistry and biochemistry
• Take Home Message
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