1. Unit 5:the Structure and Function of Macromolecules
That’s a Lot of Mers!

2. These Themes Recur Throughout Biology
There is a natural hierarchy of structural level in biological organization
As we move up the hierarchy, new properties emerge due to interactions of the lower subunits
Form fits function!

3. Polymer Principle Vocabulary
Many parts
MONOMER:
Subunit of a polymer
MACROMOLECULE:
Large organic polymer

4. Polymer Principle There are 4 classes of organic polymers:
Carbohydrates
Lipids
Proteins
Nucleic acids

5. Most polymerization Reactions are condensation reactions (dehydration synthesis). This requires energy and enzymes or catalysts. Y X OH OH

6. A Plethora of Polymers Can be Built From a Small Set of Monomers
Macromolecules are the basis for the unity and diversity of life:
UNITY: monomers are used to make all macromolecules
DIVERSITY: New properties emerge when monomers are arranged in different ways.

7. CARBOHYDRATES Organic molecules made of sugars and their polymers
Sugars are used for fuel and a carbon source
Carbo monomer: Monosaccharides
Polymers formed by condensation reactions
Classified by the number of simple sugars

8. Monosaccharides Single Sugars CHO 2:1 H to 0 ratio
Made in photosynthesis
Energy stored in bonds
Combined in condensation reactions into Di and Polysaccharides

9. Characteristics of a sugar
OH is attached to each Carbon except 1, which is double bonded to an O (carbonyl).
Aldehyde Ketone
H O H
C H---C---H
H—C---OH C==O
HO---C---H HO—C---H
H---C---OH H---C---OH
H H
Glucose (aldose) Fructose (Ketose)

10. The size of the Carbon Skeleton varies from 3-7 carbons
Classification
Number of C’s
Name
TRIOS 3
Glyceraldehyde
PENTOSE 5
Ribose
HEXOSE 6
Glucose

11. The Spatial arrangement around asymmetric Carbons may vary.
Glucose and Fructose are Enantiomers

12. In aqueous solutions, many monosaccharides form rings
In aqueous solutions, many monosaccharides form rings. Chemical equilibrium favors the ring structure because of the increased stability.
Linear form of glucose
Ring form of glucose

13. Disaccharides Joined by GLYCOSIDIC LINKAGE: A covalent bond formed by a condensation Rx between two monomers. OH
This is a 1-4 Glycosidic Linkage

14. Some Common Disaccharides
Monomers
Comments
Maltose
Glucose+Glucose
Used in Beer Making
Lactose
Glucose+Galactose
Sugar in Milk
Sucrose
Glucose+Fructose
Table Sugar

15. Polysaccharides Structural and Storage roles
Polymers of a few monosaccharides
Formed by linking monomers in enzyme-mediated condensation reactions
2 Main Functions
1.)Energy Storage:
starch and glycogen
2.)Structural Support:
cellulose and chitin

16. STORAGE: STARCH Glucose polymer Storage in plants
Helical glucose polymer with alpha 1-4 linkage (Campbell 5.6)
Stored as granules within plant organelles called PLASTIDS
Amylose: Unbranched polymer
Amylopectin: Branched polymer
Most animals have digestive enzymes to hydrolyze starch

17. STORAGE: GLYCOGEN
Large glucose polymer more highly branched than amylopectin
Storage polysaccharide in animals
Alpha 1-4 and alpha 4-6 linkages
Stored in muscle and liver of vertebrates

18. Structural Polysaccharides
CELLULOSE
Linear and unbranched
Polymer of D-glucose
In alpha 1-4 and beta 4-6 linkages
Major component of plant cell walls
Differs from starch in it’s glycosidic linkages
Can’t be digested by most organisms: They can’t hydrolyze the B-4 linkage
CHITIN
Polymer of amino sugar (Campbell 5.9): Beta glucose with an N group replacing hydroxyl on C-2
Forms exoskeletons
Can form cell walls in some fungi