Post on 11-Jan-2016
AP Biology
Macromolecules
AP Biology
Macromolecules Smaller organic molecules join
together to form larger moleculesMacromolecules
4 major classes of macromoleculesCarbohydrates
Lipids
Proteins
Nucleic acids
AP Biology
Polymers
Long molecules built by linking chain of repeating smaller units
Polymers
Monomers = repeated small units
Covalent bonds
Fig. 5-2a
Dehydration removes a watermolecule, forming a new bond
Short polymer Unlinked monomer
Longer polymer
Dehydration reaction in the synthesis of a polymer
HO
HO
HO
H2O
H
HH
4321
1 2 3
(a)
AP Biology
How to build a polymer Condensation reaction
Dehydration synthesis
Joins monomers by “taking” water out1 monomer provides OH
Other monomer provides H
Together they form water
Requires energy and enzymes
Fig. 5-2b
Hydrolysis adds a watermolecule, breaking a bond
Hydrolysis of a polymer
HO
HO HO
H2O
H
H
H321
1 2 3 4
(b)
AP Biology
How to break down a polymer Hydrolysis
Use water to break apart monomersReverse of condensation reaction
Water is split into H and OH
H and OH group attach where the covalent bond used to be
Example:
digestion is hydrolysis
AP Biology
Carbohydrates
AP Biology
Carbohydrates Composed of C,H,O
Carbo –hydr --ateCH2O(CH2)x C6H12O6
FunctionEnergy Raw materialsEnergy storageStructural materials
Monomer: sugars Example: sugars and starches
AP Biology
Sugars
Most names for sugars end in –ose Classified by number of carbons
6C = hexose (glucose)
5C = pentose (fructose, ribose)
3C = triose (glyceraldehyde)
Dihydroxyacetone
Ribulose
Ket
ose
sA
ldo
ses
Fructose
Glyceraldehyde
Ribose
Glucose Galactose
Hexoses (C6H12O6)Pentoses (C5H10O5)Trioses (C3H6O3)
Functional Groups?
AP Biology
Sugar structure
5C and 6C sugars form rings in aqueous solutions
In cells!
AP Biology
Numbered carbons
AP Biology
Simple and complex sugars
MonosaccharidesSimple 1 monomer sugarsGlucose
Disaccharides2 monomersSucrose
PolysaccharidesLarge polymersstarch
AP Biology
Building sugars
Dehydration synthesis
AP Biology
Building sugars
Dehydration synthesis
AP Biology
Polysaccharides
Polymers of sugarsCosts little energy to build
Easily reversible = release energy
FunctionEnergy storage
Starch (plants)
Glycogen (animals)
Building materials – structureCellulose (plants)
Chitin (arthropods and fungi)
Fig. 5-6
(b) Glycogen: an animal polysaccharide
Starch
GlycogenAmylose
Chloroplast
(a) Starch: a plant polysaccharide
Amylopectin
Mitochondria Glycogen granules
0.5 µm
1 µm
AP Biology
Polysaccharide diversity
Molecular structure determines function
Isomers of glucose
How does structure influence function….
Glucose Glucose
AP Biology
Digesting starch vs. cellulose
(b) Starch: 1–4 linkage of glucose monomers
(c) Cellulose: 1–4 linkage of glucose monomers
Fig. 5-9
Glucosemonomer
Cellulosemolecules
Microfibril
Cellulosemicrofibrilsin a plantcell wall
0.5 µm
10 µm
Cell walls
Cellulose is most abundant organic compound on earth
Fig. 5-10
The structureof the chitinmonomer.
(a) (b) (c)Chitin forms theexoskeleton ofarthropods.
Chitin is used to makea strong and flexiblesurgical thread.