I. Why is carbon such an important building block of life?

A. tendency to form four bonds
B. carbon skeletons
C. organic molecules contain carbon
1. some are man made
2. many are produced inside organisms
3. carbohydrates, proteins, nucleic acids, lipids

II. Monomers and polymers

A. large organic molecules consist of many repeated subunits
B. different arrangements of the subunits result in different properties
C. dehydration synthesis (condensation reactions)
D. hydrolysis

III. Carbohydrates

A. monosaccharides (simple sugars)
1. the monomers of carbohydrates
2. examples - glucose, fructose
B. disaccharides
1. a sugar molecule with 2 monomers
2. example - sucrose (table sugar)
C. oligosaccharides
1. several monomers in one molecule
2. some important components of the cell membranes
D. polysaccharides
1. many monomers in one molecule
2. starch (branched)
3. glycogen (even more branched)
4. cellulose (not branched)
5. chitin (a derivative carbohydrate)
E. glycosidic linkage - the covalent bond formed between two monosaccharides
F. functions of carbohydrates
1. energy storage (starch, glycogen, simple sugars)
2. support, protection, structure (cellulose, chitin)

G. There are different types of glycosidic linkages
1. different linkages result in different properties
2. compare and stretch cellulose

IV. Proteins

A. amino acids
1. the monomers of proteins
2. there are 20 found in organisms
3. amino group, carboxyl group, H, R
B. peptide linkage
1. covalent bond between 2 amino acids
2. occurs through dehydration synthesis
C. polypeptide
1. a chain of amino acids
D. some proteins are made of single polypeptides (example: lysozyme)
E. some proteins consist of multiple polypeptides (example: hemoglobin)
F. general shapes of proteins
1. globular
2. fibrous
G. four levels of protein structure
1. primary structure - sequence of amino acids
2. secondary structure - localized folding and twisting
a) alpha helices
b) beta pleated sheets
c) hydrogen bonds
3. tertiary structure - overall shape of one polypeptide
a) hydrogen bonds
b) disulfide bonds
4. quaternary structure - overall shape of a protein with 2 or more polypeptide subunits
H. prosthetic groups - chemicals attached to a protein (example: heme group in hemoglobin)
I. chaperone proteins - proteins that help other proteins achieve their intended shape during assembly
J. proteins have many functions
1. structure (keratin, spider's silk)
2. contraction (muscle proteins)
3. storage (albumin)
4. defense (antibodies)
5. transport (hemoglobin)
6. signal (some hormones)
7. enzymes (lactase)
K. a protein's environment can alter its shape
1. denature, renature
2. temperature
3. pH
4. salt concentration
L. proteins and apoptosis
1. caspases
2. cancer, Alzheimer's
3. development
M. Linus Pauling

V. Nucleic Acids

A. nucleotides
1. the monomers of nucleic acids
2. 5-carbon sugar, phosphate group, nitrogenous base
3. 4 different nucleotides in DNA; 4 in RNA
B. phosphodiester linkage
1. covalent bond between nucleotides
2. links sugar of one to phosphate group of other; a sugar-phosphate backbone
3. nitrogenous base attaches to sugar
C. DNA is copied and passed on to new cells. DNA is copied and passed on to new generations.
D. DNA -> RNA -< protein synthesis
E. where is DNA found?
F. Watson and Crick (1953), Rosalin Franklin

VI. Lipids

A. fats and oils (triglycerides)
1. glycerol + 3 fatty acids
2. ester linkage
3. saturated
4. unsaturated
5. hydrogenated
B. phospholipids
1. P-containing compound + glycerol + 2 fatty acids
2. cell membranes
C. waxes
1. an alcohol + 1 fatty acid

D. carotenoids
1. see text for chemical structures
2. example = beta-carotene (vitamin A)
E. steroids
1. 3 six-sided rings + 1 free five-sided ring + additional atoms
2. examples = cholesterol, testosterone, estrogens
F. additional functions of lipids
1. energy storage
a. animals tend to store energy in lipids (triglycerides)
b. plants tend to store carbohydrates (starch, sugar)
c. seeds often contain triglycerides
2. protection from environment
a. cushioning (fats)
b. waterproofing (oils, waxes)
c. insulation (blubber)
d. protection from mold (waxes)