This document provides an overview of carbohydrates: - Carbohydrates are composed of carbon, hydrogen, and oxygen. They function to provide energy and act as structural materials. The basic units are sugars. - The main types of sugars are monosaccharides like glucose and fructose, disaccharides like sucrose, and polysaccharides like starch and cellulose. - Polysaccharides are polymers of sugars that provide efficient energy storage in plants and animals. Starch and glycogen are examples of branched polysaccharides for energy storage, while cellulose provides structure in plants.

1. AP Biology
Carbohydrates

2. AP Biology 2006-2007
OH
OH
H
H
HO
CH2OH
H
H
H
OH
O
Carbohydrates
energy
molecules

3. AP Biology
Carbohydrates
 Carbohydrates are composed of C, H, O
carbo - hydr - ate
CH2O
(CH2O)x C6H12O6
 Function:
 energy  energy storage
 raw materials  structural
materials
 Monomer: sugars
 ex: sugars, starches, cellulose
sugar sugar sugar sugar sugar sugar sugar
sugar
C6H12O6
(CH2O)x

4. AP Biology
Sugars
 Most names for sugars end in -ose
 Classified by number of carbons
 6C = hexose (glucose)
 5C = pentose (ribose)
 3C = triose (glyceraldehyde)
OH
OH
H
H
HO
CH2OH
H
H
H
OH
O
Glucose
H
OH
HO
O H
H
HO
H
Ribose
CH2OH
Glyceraldehyde
H
H
H
H
OH
OH
O
C
C
C
6 5 3

5. AP Biology
Functional groups determine function
carbonyl
ketone
aldehyde
carbonyl

6. AP Biology
Sugar structure
5C & 6C sugars form rings in solution
Carbons are numbered
Where do
you find solutions
in biology?
In cells!

7. AP Biology
Numbered carbons
C
C
C
C
C
C
1'
2'
3'
4'
5'
6'
O
energy stored in C-C bonds

8. AP Biology
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Simple & complex sugars
 Monosaccharides
 simple 1 monomer sugars
 glucose
 Disaccharides
 2 monomers
 sucrose
 Polysaccharides
 large polymers
 starch
OH
OH
H
H
HO
CH2OH
H
H
H
OH
O
Glucose

9. AP Biology
Building sugars
 Dehydration synthesis
glycosidic linkage
|
glucose
|
glucose
monosaccharides disaccharide
|
maltose
H2O

10. AP Biology
Building sugars
 Dehydration synthesis
|
fructose
|
glucose
monosaccharides
|
sucrose
(table sugar)
disaccharide
Let’s go to the
videotape!
H2O
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

11. AP Biology
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)
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

12. AP Biology
Linear vs. branched polysaccharides
starch
(plant)
glycogen
(animal)
energy
storage
What does
branching do?
Let’s go to the
videotape!
slow release
fast release

13. AP Biology
Polysaccharide diversity
 Molecular structure determines function
 isomers of glucose
 structure determines function…
in starch in cellulose

14. AP Biology
Digesting starch vs. cellulose
starch
easy to
digest enzyme
enzyme
cellulose
hard to
digest

15. 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
But it tastes
like hay!
Who can live
on this stuff?!

16. Regents 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

17. Regents Biology
Q
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k
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p
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.
Helpful bacteria
 How can herbivores digest cellulose so well?
 BACTERIA live in their digestive systems & help digest
cellulose-rich (grass) meals
Ruminants
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Tell me about
the rabbits,
again, George!
I eat
WHAT!
Caprophage

18. Regents Biology 2006-2007
Let’s build some
Carbohydrates!
EAT
X