Title: Lecture 5 Sept 9, 2005
1Lecture 5 Sept 9, 2005 MACROMOLECULES 1
Carbohydrates
And Lipids
2Lecture outline
- Polymers
- Carbohydrates
- monomers and polymers
- Lipids
3Principles of Building Polymers
- biological polymers are built from simple small
units called monomers
- addition of each monomeric unit occurs with the
- removal of a water molecule
A condensation dehydration reaction
- ends are chemically distinct
- directionality of synthesis
-
- requires energy input for polymerization
- uses carrier molecules to activate monomers
4MODULAR DESIGN SIMPLICITY AND
VERSATILITY ASSEMBLY-LINE MENTALITY
Dont have to make every structure from
scratch Simplified chemistry, repeating link
Dehydration Synthesis
5Monomers
H-XXXX-OH
H-YYY-OH
H-ZZZZZ-OH
Dehydration Synthesis make by taking water away
H-XXXX-
YYY-
ZZZZZ-OH
HOH
HOH
Polymer
6Endless variety of Polymers Order of
Monomers Different Amounts of each monomer
H-XXXX-
YYY-
ZZZZZ-OH
H-YYY-XXXX-
ZZZZZ-OH
H-XXXX-
ZZZZZ-
YYY-OH
H-ZZZZZ-
YYY-
ZZZZZ-OH
7- Monomers form larger molecules by condensation
reactions called dehydration reactions
8- Polymers can disassemble by
- Hydrolysis
9Polymers
Monomers
10CARBOHYDRATES Sugars and Sugar Derivatives
Polymers
Monomers
Polysaccharides
Monosaccharides
Simple Sugars Glucose Fructose
Ribose
Long chains of monomers
storage starch amylose amylopectin
glycogen structure Fiber cellulose
Oligosaccharides Informational structures
11MONOSACCHARIDES Carbohydrate Monomers
O
O
- 1 Carbonyl - aldehyde or ketone
R-C-H R1-C-R2
R-OH
- All Other CARBONS
- each have ONE alcohol group
Expect them to be HYDROPHILIC
Aldo sugar
Keto sugar
12Monosaccharides Vary in length 3, 4, 5,
6 or 7 carbons
13Also differ by SPATIAL GEOMETRY
Carbon with 4 different functional groups
Chiral or asymmetric carbon handed carbon
14Plane of symmetry
Left handed L form
Right handed D form
Stereoisomers not the same
15Not chiral
Chiral
Chiral
Chiral
Chiral
Not chiral
16Spatial Geometry yields a variety of forms
8 Forms!
175 and 6 Carbon Sugars CIRCULARIZE in Water To
FORM RINGS
Haworth projection
Fischer projection
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19Circularization causes another chiral carbon
b-D-Glucose
a-D-Glucose
20monomeric sugars coupled together by
CONDENSATION REACTION
Glycosidic bond
Holds carbohydrates together
21Synthesis Requires Energy Input
Breakdown Does not Require Energy Input
22Disaccharides, Oligosaccharides and
Polysaccharides
(two)
(few)
(many)
Sucrose (glucose fructose) Cane Sugar Lactose
(glucosegalactose) Milk Sugar Maltose
(glucoseglucose) Beer
DiSaccharides
OligoSaccharides
Dextran (short chain of glucose) Digested Starch
Furans (short chain of fructose) Onions
23Polysaccharides
- Long chains of Millions of monomers
- most common polymers made ONLY of GLUCOSE
monomers - Storage reserves
- Starch amylose
- amylopectin, glycogen
- Structure cellulose
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25Glycogen (or Amylopectin)
Polysaccharides of glucose chains in an a(1-gt4)
linkage, with a(1-gt6) branches
26Structural Polysaccharides
- Cellulose
- Is also a polymer of glucose
- But has different glycosidic linkages than starch
- We can readily digest starches
- but cannot digest cellulose
27- Cellulose is indigestable to animals
- Cows and termites have microbes in their stomachs
to facilitate this process
28Starches a glycosidic linkage OH down
Cellulose b glycosidic linkage OH up
29Cellulose ß(1-gt4) linkage Amylose a(1-gt4)
linkage
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31Starch
Polysaccharides although hydrophillic are general
ly Insoluble in water
polymer effect
- orders too much water around polymer
- Polymer tends to hydrogen bond to itself
- Polymer falls out of solution
32Polymer forms Secondary Structures Polymer
hydrogen bonding to Itself
33If Denature Secondary Structure (Break Hydrogen
Bonds of Polymer with Itself) Water will
Hydrogen bond With Polymer
RESULT IS BOUND WATER GEL
34Can FORCE polymer to stay Hydrated Sugar
Derrivatives
- Disrupt
- Secondary
- Structures
- remain
- Hydrated!
Characteristics?
35Some Other Sugar Derivatives or Modified Sugars
Missing one or more components a. 5 carbon
RIBOSE and DEOXYRIBOSE
missing one alcohol b. Glycerol - 3 Carbon
Sugar with alcohol in place of an aldehyde c.
Sugar amines, Sugar acids have amine or
carboxylic acid group or something else in
place of an alcohol
a.
H
H
H
H
-
-
-
b.
H - C - C - C - H
-
-
-
OH
OH
OH
c.
36Questions?
37LIPIDS hydrophobic character
Steroids
Triglycerides
Phospholipids
Membranes Hormones
FATS OILS -long term storage depot
MEMBRANES
Other
Fatty Acids and Glycerol
38Fatty Acid carboxylic acid with LONG hydrocarbon
chain
Chain length
saturation
39- Fats
- Are constructed from two types of smaller
molecules, a single glycerol and usually three
fatty acids
H
H
H
H
H
H
H
H
O
H
H
H
H
H
H
H
H
Figure 5.11
(b) Fat molecule (triacylglycerol)
40ESTER Linkage
41Triglycerides
Properties in Water
42FATS
OILS
WHY?
Like Fig 3-28
43- Saturated fatty acids
- Have the maximum number of hydrogen atoms
possible - Have no double bonds
Stack nicely
44- Unsaturated fatty acids
- Have one or more double bonds
Do not Stack well
45monolayer
Free Fatty Acids Hydrolyzed Triglycerides
micelle
Fatty Acids
amphipathic
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47Phospholipids
Glycerol linked to 2 fatty acids
Fig 3-27
Phosphate
Head Group
Glycerol
Fatty acid tails
Fatty acid tails
Nonpolar
Polar
48- Phospholipid structure
- Consists of a hydrophilic head and hydrophobic
tails
49Phospholipid Head Groups
Hydrophillic! Polar groups
50Phospholipid Bilayer
Form Boundaries
51WATER
Hydrophilic head
Polar Headgroups
Nonpolar FA tails
Hydrophobic tail
Polar Headgroups
WATER
Figure 5.14
52Sheet
Outside
Inside
3-D Ball (Sphere) Vesicle or Liposome
Cross section
53Hormones Signal molecules
54Summary
- Principles of Building Polymers
- Directional assembly from simple units
- Requires energy input
- Condensation dehydration reactions
- Carbohydrates
- monosaccharides
- polysaccharides
- Lipids
- Triglycerides
- phospholipids
- steroids
55Next Time More Macromolecules Proteins
Nucleic Acids