Download Document

Carbohydrates
AP Biology
CH2OH
H
O
H
OH
H
H
OH
HO
H
OH
Carbohydrates
energy
molecules
AP Biology
2006-2007
Carbohydrates
 Carbohydrates are composed of C, H, O

carbo - hydr - ate
CH2O
(CH22O)
O)xx
C66H12
O
(CH
12 66
Function:
energy
 raw materials
materials

energy storage
 structural

 Monomer: sugars
 ex: sugars, starches, cellulose
AP Biology sugar sugar sugar sugar sugar sugar sugar
sugar
Sugars
 Most names for sugars end in -ose
 Classified by number of carbons
6C = hexose (glucose)
 5C = pentose (ribose)
 3C = triose (glyceraldehyde)

CH2OH
H
O
H
OH
6H
HO
H
AP Biology
OH
Glucose
H
CH2OH
OH
C
O
H
HO
H
5
OH
O
H
HO
H
Ribose
H
H
H
C
OH
C
3OH
H
Glyceraldehyde
Simple & complex sugars
 Monosaccharides
simple 1 monomer sugars
 glucose

 Disaccharides
2 monomers
 sucrose

 Polysaccharides
large polymers
 starch

AP Biology
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
CH2OH
H
O
H
OH
H
H
OH
HO
Glucose
H
OH
Building sugars
 Dehydration synthesis
monosaccharides
|
glucose
AP Biology
H2O
|
glucose
disaccharide
|
maltose
glycosidic linkage
Building sugars
 Dehydration synthesis
monosaccharides
|
glucose
AP Biology
H2O
|
fructose
Let’s go to the
videotape!
disaccharide
|
sucrose
(table sugar)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Polysaccharides
 Polymers of sugars
costs little energy to build
 easily reversible = release energy

 Function:

energy storage
 starch (plants)
 glycogen (animals)
 in liver & muscles

structure
 cellulose (plants)
 chitin (arthropods & fungi)
AP Biology
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Linear vs. branched polysaccharides
slow release
starch
(plant)
energy
storage
glycogen
(animal)
AP Biology
fast
release
Polysaccharide diversity
 Molecular structure determines function
in starch
in cellulose
isomers of glucose
 structure determines function…

AP Biology
Digesting starch vs. cellulose
starch
easy to
digest
enzyme
cellulose
hard to
digest
enzyme
AP Biology
Cellulose
 Most abundant organic
compound on Earth
herbivores have evolved a mechanism to
digest cellulose
 most carnivores have not

 that’s why they
eat meat to get
their energy &
nutrients
 cellulose = undigestible roughage
AP Biology
Cow
can digest cellulose well;
no need to eat other sugars
Gorilla
can’t digest cellulose well;
must add another sugar
source, like fruit to diet
Regents Biology
Helpful bacteria
 How can herbivores digest cellulose so well?

BACTERIA live in their digestive systems & help digest
cellulose-rich (grass) meals
a dna ™emiTkciuQ
rosserpmoced )desserpmocnU( F FIT
.erutcip siht ees ot dedeen era
Caprophage
Ruminants
Regents Biology