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OUTLINE:

POLYMERS

CONDENSATION REACTIONS
HYDROLYSIS

MONOSACCHARIDES
DISACCHARIDES
GLYCOSIDIC LINKAGE

POLYSACCHARIDES

STORAGE POLYSACCHARIDES
GLYCOGEN
STARCH
STRUCTURAL POLYSACCHARIDES
CELLULOSE
CHITIN PEPTIDOGLYCAN

A. POLYMERS

.

"just as atoms make up molecules, small molecules make up bigger ones (polymers)"

1. POLYMER = large molecule consisting of many monomers

2. MONOMER = Subunit of polymer

3. MACROMOLECULE = LARGE ORGANIC POLYMER;

4 classes:

CARBOHYDRATES (today), LIPIDS, PROTEINS, NUCLEIC ACIDS

MAKING AND BREAKING POLYMERS

MAKING is Usually via CONDENSATION REACTIONS

(FIG. 5.2)

one monomer loses an OH- and the other loses a H+

BREAKING is usually via HYDROLYSIS

HYDROLYSIS = Breaking via addition of water

example of hydrolytic digestive enzymes

.

B. CARBOHYDRATES

= SUGARS (= monomers) and POLYMERS of SUGARS

.

1. MONOSACCHARIDES = simple sugars (CH2O)n ; 3 to 7 Carbons (-OHs and =Os)

Major nutrients (C and energy sources)

Monomers for bigger carbohydrates

(examples: FIG. 5.3)

a. Ketoses and aldoses

b. Most common sugars are trioses, pentoses or hexoses

c. Galactose vs. Glucose: stereoisomers (i.e. w/ asymmetric C)

d. Ring structure = actual form most of the time

(see FIG. 5.4) .

2. DISACCHARIDES = 2 MONOs joined by a GLYCOSIDIC LINKAGE

.

Condensation reactions

(see Fig. 5.5)

examples:

MALTOSE = glucose + glucose (beer making)

LACTOSE = glucose + galactose (milk sugar)

SUCROSE = glucose + fructose (table sugar, also in plant sap)

.

3. POLYSACCHARIDES

.

a. STORAGE POLYSACCHARIDES, are hydrolyzed by cells to yield monomers

.

STARCH = STORAGE Polysaccharides IN PLANTS

(see Fig. 5.6)

Alpha 1-4 linkages

Plastids (including chloroplasts see Fig. 5.6a)

Animals can digest (potatoes and grains)

.

GLYCOGEN - STORAGE Polysaccharides IN ANIMALS,

AND SOME MICROORGANISMS

(see Fig. 5.6b)

stored in muscle and liver

very highly branched

.

b. STRUCTURAL POLYSACCHARIDES

.

CELLULOSE - plant and some fungal cell walls

(Fig. 5.8 and 5.7)

Beta 1-4 linkages

Linear

Animals can't digest but many bacteria and fungi can (cow rumen, termite gut)

.

CHITIN

(Fig. 5.9)

show structure: monomer = an amino sugar (N-Acetylglucosamine)

Exoskeleton of Arthropods

Many Fungal cell walls

Also used as surgical thread

(Fig. 5.9b)

.

.

PEPTIDOGLYCAN show D-amino acids etc.(in class)