1. Chapter 4: Carbon Do Now: How many bonds can carbon form?

2. Organic Compounds Compounds that contain carbon
Most contain Hydrogen atoms as well as carbon.
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

3. Carbon (The Backbone of life)
Body consists of carbon based compounds (ex: proteins, lipids, carbohydrates, DNA)
Carbon can form up to 4 bonds
Most frequent partners are O, H, N
Carbon chains form the skeleton of most organic molecules
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

4. Hydrogen (valence = 1) Oxygen (valence = 2) Nitrogen (valence = 3)
Fig. 4-4
Hydrogen
(valence = 1)
Oxygen
(valence = 2)
Nitrogen
(valence = 3)
Carbon
(valence = 4) H O N C
Figure 4.4 Valences of the major elements of organic molecules

5. Tetravalance Carbon can form 4 covalant bonds with a variety of atoms
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

6. Tetrahedron
In molecules with multiple carbons, each carbon bonded to four other atoms has a tetrahedral shape
When 2 carbons are joined by a double bond, the molecules is flat in shape
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

7. Hydrocarbons Organic molecules consisting of only carbon and hydrogen
Non-polar molecules (fats)
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

8. Carbon Skeletons
Why do we study carbon -- is it the most abundant element in living organisms?
H & O most abundant
C is the next most abundant

9. Isomers
Molecules with same molecular formula but different structures (shapes)
different chemical properties
different biological functions
Same formula but different structurally & therefore different functionally. Molecular shape determines biological properties.
Ex. Isomers may be ineffective as medicines
6 carbons
6 carbons
6 carbons

10. Structural: different covalent arrangement
Fig. 4-7
Structural: different covalent arrangement
Pentane
2-methyl butane
(a) Structural isomers
Geometric: same covalent arrangements, different spatial arrangements
cis isomer: The two Xs are
on the same side.
trans isomer: The two Xs are
on opposite sides.
(b) Geometric isomers
Figure 4.7 Three types of isomers
Enantiomers: isomers that are mirror images
L isomer
D isomer
(c) Enantiomers

11. Isomers- Form affects function
Structural differences create important functional significance
medicines
L-version active
but not D-version
sometimes with tragic results…

12. Form affects function Thalidomide
prescribed to pregnant women in 50s & 60s
reduced morning sickness, but…
stereoisomer caused severe birth defects

13. Effective Enantiomer Ineffective Enantiomer Drug Condition Pain;
Fig. 4-8
Effective
Enantiomer
Ineffective
Enantiomer
Drug
Condition
Pain;
inflammation
Ibuprofen
S-Ibuprofen
R-Ibuprofen
Figure 4.8 The pharmacological importance of enantiomers
Albuterol
Asthma
R-Albuterol
S-Albuterol

14. Functional groups
Parts of organic molecules that are involved in chemical reactions
give organic molecules distinctive properties
 hydroxyl  amino
 carbonyl  sulfhydryl
 carboxyl  phosphate
Affect reactivity
makes hydrocarbons hydrophilic
increase solubility in water

15. Hydroxyl –OH organic compounds with OH = alcohols
names typically end in -ol
ethanol

16. Carbonyl C=O O double bonded to C if C=O at end molecule = aldehyde
if C=O in middle of molecule = ketone

17. Carboxyl –COOH C double bonded to O & single bonded to OH group
compounds with COOH = acids
fatty acids
amino acids

18. Amino -NH2 N attached to 2 H compounds with NH2 = amines
amino acids
NH2 acts as base
ammonia picks up H+ from solution

19. Sulfhydryl –SH S bonded to H compounds with SH = thiols
SH groups stabilize the structure of proteins

20. Phosphate –PO4 P bound to 4 O connects to C through an O
lots of O = lots of negative charge
highly reactive
transfers energy between organic molecules
ATP

21. Look at the difference
Basic structure of male & female hormones is identical
identical carbon skeleton
attachment of different functional groups
interact with different targets in the body
different effects
For example the male and female hormones, testosterone and estradiol, differ from each other only by the attachment of different functional groups to an identical carbon skeleton.

22. Diversity of molecules
Substitute other atoms or groups around the carbon
ethane vs. ethanol
H replaced by an hydroxyl group (–OH)
nonpolar vs. polar
gas vs. liquid
biological effects!
ethane (C2H6)
ethanol (C2H5OH)