1. CARBON AND MOLECULAR DIVERSITY
CHAPTER 4
CARBON AND MOLECULAR DIVERSITY

2. THE IMPORTANCE OF CARBON
ORGANIC CHEMISTRY-focuses on the study of carbon
ORGANIC MOLECULES-contain carbon
VITALISM-early 19th century; belief in a life force outside the jurisdiction of chemical/physical laws
MECHANISM-shift from vitalistic thought; belief that all natural phenomena are governed by physical and chemical laws

3. CARBON ATOMS:VERSATILE MOLECULAR BUILDLING BLOCKS
THE CARBON ATOMS:
Usually has an atomic number of 6
Therefore it has 4 valence electrons
Completes its outer shell by forming 4 covalent bonds
TETRAVALENT ELECTRON CONFIGURATIONS
Carbon becomes central figure in large molecules
Carbon can bond easily with many different elements’
LOOK AT THE FOUR MAJOR ATOMIC COMPONENTS OF ORGANIC MOLECULES

4. ATOMS CARBON BONDS EASILY WITH
HYDROGEN
OXYGEN
NITROGEN
CARBON

5. VARIATION IN CARBON SKELETONS
Covalent bonds link carbon atoms together in long chains that form the skeletal framework for organic molecules. These carbon skeletons may vary in:
LENGTH
SHAPE (STRAIGHT CHAIN, BRANCHED,
RING)
-NUMBER AND LOCATION OF DOUBLE BONDS
THIS VARIATION IN CARBON SKELETONS CONTRIBUTES TO THE COMPLEXITY AND DIVERSITY OF ORGANIC MOLECULES

6. HYDROCARBONS- molecules containing only carbon and hydrogen
Make fossil fuels from long dead organisms
Are hydrophobic because C-C and C-H bonds are nonpolar

7. ISOMERS
ISOMERS ARE COMPOUNDS WITH THE SAME MOLECULAR FORMULA BUT WITH DIFFERENT STRUCTURES AND HENCE DIFFERENT PROPERTIES
THERE ARE 3 TYPES OF ISOMERS
1) STRUCTURAL-differ in the covalent arrrangement of their atoms
2) GEOMETRIC-have the same covalent bonding, but differ in spatial relationships
3) ENANTIOMERS-mirror images

8. 3 TYPES OF ISOMERS

9. FUNCTIONAL GROUPS SMALL GROUPS OF ATOMS THAT ARE BONDED TO
THE CARBON SKELETON OF ORGANIC MOLECULES
-THEY HAVE SPECIFIC CHEMICAL AND
PHYSICAL PROPERTIES
-ARE THE REGIONS OF ORGANIC MOLECULES
THAT ARE CHEMICALLY REACTIVE
-THEY BEHAVE CONSISTENTLY
-CREATE UNIQUE CHEMICAL PROPERTIES
OF ORGANIC MOLECULES THEY ARE FOUND IN

10. HYDROXYL GROUP
Consists of a hydrogen atom bonded to an oxygen atom, which is in turn bonded to carbon (-OH)
Is a polar group; the bond between O-H is polar
Makes the molecule to which it is attached water soluble
Organic compounds with hydroxyl groups are called alcohols

11. CARBONYL GROUP CONSISTS OF A CARBON ATOM DOUBLE-BONDED TO OXYGEN (-CO)
IS A POLAR GROUP
FOUND IN SUGARS
ALDEHYDE- THE CARBONYL IS AT THE END OFF THE CARBON SKELETON
KETONE- THE CARONYL IS AT THE END OF THE CARBON SKELETON

12. CARBOXYL GROUP
Consists of a carbon atom which is both double-bonded to an oxygen and single bonded to the oxygen of a hydroxyl group (-COOH)
Is polar and water soluble
The covalent bond between oxygen and hydrogen is so polar that the hydrogen reversibly dissociates as H+.
Since it donates protons, this group has acidic properties
Compounds with this functional group are called carboxylic acids

13. FUNCTIONAL GROUPS
AMINO GROUP AND CARBOXYL GROUP

14. THE AMINO GROUP
Consists of a nitrogen atom bonded to two hydrogens and to the carbon skeleton(-NH2)
Is polar and water soluble
Acts as a weak base. The unshared pair of electrons on the nitrogen can accept a proton
Organic compounds with this functional group are called amines.

15. FUNCTIONAL GROUPS
AMINO GROUP AND CARBOXYL GROUP

16. THE SULFHYDRYL GROUP
Consists of an atom of sulfur bonded to an atom of hydrogen (-SH)
Help stabilize the structure of proteins
Organic compounds with this functional group are called thiols

17. THE PHOSPHATE GROUP
It is the dissociated form of phosphoric acid (H3PO4)
Loss of two proton by dissociation leaves the phosphate group with a negative charge
Has acidic properties since it loses two protons
Polar and water soluble
Important in cellular energy storage and transfer (ATP)