1. Crazy Carbon -
Chapter 4 notes

2. Carbon is responsible for the large diversity of biological molecules
Save me from Organic
Chemistry!!!
Carbon is responsible for the large diversity of biological molecules

3. Organic Molecules Compounds containing carbon
These compounds can contain thousands of atoms.
Overall percentages of major elements (C,H,O,N,S,P) are the same from one organism to the next. Because Carbon is so versatile, it can be used to build bzillions of organic molecules.
Variations in organic molecules distinguish different species

4. History Jons Jakob Berzelius
Made distinction between organic (found in living organisms) and inorganic (found in non living world).
Gave rise to Vitalism – belief in a life force outside of physical and chemical laws

5. History Friedrich Wohler Attempted to make inorganic compounds
Actually made urea – a compound found in urine (made without a living organism involved)
Started chipping away at theory of vitalism

6. History Stanley Miller
Tested whether organic molecules could arise spontaneously under conditions of early earth
Led to theory of mechanism – the view that physical and chemical laws govern all natural phenomena – including the processes of life

8. Very Versatile Building Blocks

9. Chemical Structure
Carbon has 6 electrons, 2 in the first shell, 4 in the outer shell.
So....Valence of Carbon is 4 (tetravalence)
It can bond to four other molecules
Carbon completes its valence by sharing electrons, forming covalent bonds (NOT ionic)
Shape is a tetrahedron (109˚)
Most frequent partners are O, H, and N

10. Simple Carbon Molecules
CH4--Methane-4 single bonds, tetrahedron shape

11. Simple Carbon Molecules
CO2--Carbon Dioxide-source of Carbon for all organic molecules found in organisms (due to photosynthesis).
Chemical formula O=C=O

12. Complex Carbon Molecules
Carbon can bond to other carbon molecules forming long chains These are the skeletons of organic molecules
Carbon skeletons can be straight, branched, or arranged in rings

13. Figure 4.4 Variations in carbon skeletons

14. Hydrocarbons Long chains containing only carbon and hydrogen
Major component of petroleum
Not prevalent in living things, but some organic molecules, like fat, have regions of hydrocarbons.
Hydrocarbons are hydrophobic because the bonds are nonpolar.
Store lots of energy (gas in a car, fat in animals)

15. Figure 4.5 The role of hydrocarbons in fats

16. Interesting Isomers
Same molecular formula, but different structure and different properties.

17. Structural Isomers
Differ in covalent arrangement of their atoms. The longer the carbon skeleton, the more structural isomers.
Location of double bonds can also differ

18. Geometric Isomers
Same covalent partnership, different spatial arrangements
Result of inflexible double bonds (atoms attached to a double bond can’t rotate freely)
The different shapes affect biological activities.
ex. Vision involves light changing chemical rhodopsin from one geometric isomer to another.

20. Enantiomers
Mirror images formed when carbon is attached to four different atoms. The middle Carbon is asymmetric!!
Cells can distinguish enantiomers based on their different shapes. One is “active” and the other is “inactive”.
ex. Pharmaceuticals....sometimes drug isomers produce no effect or harmful effects on patients

21. Figure 4.7 The pharmacological importance of enantiomers

22. What kind of isomer
am I???

23. Functional Groups
Components of organic molecules that are most commonly involved in chemical reactions.
Number and arrangement of functional groups give molecules their unique properties.
All are hydrophilic, so soluble in water
Usually attached to a carbon on the skeleton
ex. Estradiol and Testosterone--have same structural backbone, but different functional groups that cause one to take care of feminine qualities and other one mighty maleness.

25. Hydroxyl -OH or -HO
Organic compounds containing hydroxyl groups are called ALCOHOLS
Polar because O is really electronegative!!! This attracts water molecules and helps dissolve
ex. Sugars

26. Carbonyl > CO Carbon atom joined to oxygen by a double bond
Aldehydes: Carbonyl group on end of carbon skeleton
Ketones: Carbonyl group in the middle of the skeleton
Variations in location of carbonyl group is source of molecular diversity
ex. Acetone (ketone) an Propanol (aldehyde) are structural isomers with different properties

27. Carboxyl -COOH
Oxygen double bonded to carbon that is also bonded to a hydroxyl (-OH)
Form carboxylic acids (organic acids)
Has acidic properties because it is a source of H+ ions. Bond between O and H is so polar that hydrogen tends to dissociate.
ex. Acetic Acid (vinegar), substance in ant stings

28. Amino -NH2
Nitrogen atom bonded to two hydrogen atoms and to carbon skeleton
Compound with this group is called an amine
Acts as a base because NH2 is able to pick up H+ ions from the surrounding solution and become NH3+. This lowers the H+ concentration!!!
ex. Amino Acids...The building
blocks of proteins!!

29. Sulfhydryl -SH Sulfur atom bonded to an atom of hydrogen
Organic compounds with this group are called thiols
ex. Help stabilize
protein structure

30. Phosphate -OPO32-
Anion formed by dissociation of phosphoric acid (H3PO4)
Loss of hydrogen ions by dissociation leaves phosphate with a negative charge.
Form organic phosphates
ex. Function in transfer of
energy between organic
molecules, ATP
(adenosine triphosphate)

31. Methyl -CH3 Methyl group attached to carbon skeleton
ex. Methyl groups may be added to DNA to inactivate certain genes

32. Table 4.1 Functional Groups of Organic Compounds