1. Carbon and the Molecular Diversity of Life
Chapter 4

2. The Backbone of Life
All living organisms are largely made up of chemicals that are based on elements of carbon
Other common ingredients include hydrogen, oxygen, nitrogen, sulfur, and phosphorous
The diversity of life is related to carbon and its ability to bond with other elements in a variety of ways

3. Organic Chemistry
All compounds containing carbon are said to be organic
Most also contain hydrogen
Be familiar with Miller’s experiment on page 59.

5. Carbon and Bonding
Carbon has 6 electrons which means only 4 are in the valance shell, leaving 4 “holes” to fill
Carbon generally shares its 4 carbon atoms via covalent bonds
In molecules, carbon can act as a hub where the molecule can branch off in as many as 4 directions (tetravalence).

6. Carbon and Molecular Diversity
Carbon skeletons vary in length
Skeletons may be branched or unbranched
The skeleton may have double bonds, which can vary in number and location
Some carbon skeletons are arranged in rings

7. Hydrocarbons Consists only of carbon and hydrogen
Ex: Major component of petroleum
Not common alone in living organisms, but are common on regions of molecules
Ex: Fat has a hydrocarbon tail attached to a nonhydrocarbon component
Tend to be hydrophobic (because nonpolar)
Reactions tend to release large amounts of energy

8. Isomers
Compounds that have the same numbers of atoms of the same elements, but different structures and properties
Structural Isomers – differ in their covalent arrangement of atoms and may fiffer in the placement of their double bonds
Geometric Isomers – have the same covalent partnerships, but they differ in their spatial arrangements
Enantiomers – isomers that are mirror images of each other
Usually 1 is biologically active and the other is not
Ex: Thalidomide use in pregnant women
“good” version reduced morning sickness
“bad” version caused birth defects

9. Functional Groups
At times, a chemical group may replace one or more of the hydrogens bonded to the carbon skeleton.
These groups may participate in reactions and may play a role in the function of the molecule because of shape

10. Functional Groups
1)Hydroxyl
Hydrophilic; increases solubility

11. Functional Groups 2) Carbonyl Hydrophilic; increases solubility
Know the difference between a ketone and an aldehyde

12. Functional Groups
3) Carboxyl
Hydrophilic; increases solubility

13. Functional Groups
4) Amino
Hydrophilic; increases solubility

14. Functional Groups
5) Sulfhydryl
Hydrophilic; increases solubility

15. Functional Groups
6) Phosphate
Hydrophilic; increases solubility

16. Functional Groups 7) Methyl Non-Reactive
Acts as a recognizable tag on biological molecules

17. ATP Adenosine Triphosphate
Organic molecule consists of an adenosine molecule attached to a string of 3 phosphate groups
A reaction with water causes the release of one of the phosphate groups also releasing energy.
Molecule becomes ADP