Download CH 2 O

Carbohydrates
AP Biology
CH2OH
H
O
H
OH
H
H
OH
HO
H
OH
Carbohydrates
Energy + structure
molecules
AP Biology
Outline
 Structure
 Monosaccharides
Hexose sugars
 Pentose sugars

 Disaccharides
 Polysaccharides

AP Biology
branching
Carbohydrates
 Carbohydrates are composed of C, H, O
carbo - hydr - ate
CH2O
(CH22O)
O)xx
C66H12
O
(CH
12 66
sugar sugar sugar sugar sugar sugar sugar
monosaccharide
disaccharide
AP Biology
polysaccharide
Sugars = FAST energy
 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
Sugar structure
5C & 6C sugars form rings in solution
Why a ring?
To make it stable!
AP Biology
Carbons are numbered
Numbered carbons
These will become
important in DNA!
C 6'
5' C
O
4' C
C1'
energy stored in C-C bonds
harvested in cellular respiration
C3'
AP Biology
C2'
Functional Group Review
hydroxyl
WHY can glucose
dissolve in water?
AP Biology
Simple vs. Complex Sugars
SIMPLE
 Monosaccharides
 Disaccharides
CH2OH
H
HO
H
OH
O H
H
OH
H
OH
AP Biology
FAST
ENERGY
COMPLEX
 Polysaccharides
ENERGY
STORAGE &
STRUCTURE
MONOsaccharides
How many sugars?
Glucose, Miss Monosaccharide
Hommie #1:
Fructose
AP Biology
Hommie #2:
Galactose
PENTOSE SUGARS
Isomers = Same chemical formula (C6H12O6)
but different arrangements
How many sugars?
DIsaccharides
 Formed by dehydration synthesis
 Glycosidic linkage is formed
 3 major disaccharides:
AP Biology
Maltose – used in beer brewing
 Dehydration synthesis
monosaccharides
|
glucose
AP Biology
H2O
|
glucose
disaccharide
|
maltose
glycosidic linkage
Sucrose – table sugar
 Dehydration synthesis
monosaccharides
|
glucose
AP Biology
H2O
|
fructose
disaccharide
|
sucrose
(table sugar)
Lactose – sugar found in milk
 Dehydration synthesis between
glucose + galactose
 Lactose-intolerance
AP Biology
Instead of taking
AWAY water, we
should…
Making and Breaking Biomolecules
• dehydration synthesis (synthesis) =
polymerization
• hydrolysis (digestion) =
depolymerization
AP Biology
POLYsaccharides
 Polymers of sugars
How many sugars?
costs little energy to build
 easily reversible = release energy

 Function:
energy storage
 structure

AP Biology
Digestion = Energy Release
Linear polysaccharide
Which
polysaccharide
releases energy
the fastest?
Branched polysaccharide
AP Biology
Faster digestion!
=
Faster energy
release!
Polysaccharides – Energy Storage
Starch
 Usually linear
 Slow energy release
 In plants!
AP Biology
Glycogen
 Usually branched
 Fast energy release
 In animals (liver,
muscles)
Polysaccahrides as Structural
Molecules
Cellulose
Chitin
Peptidoglycan
AP Biology
Let’s talk about digestion.
We eat a lot of carbohydrates…
cellulose
starch
AP Biology
glucose
Digesting starch vs. cellulose
starch
easy to
digest
enzyme
cellulose
hard to
digest
enzyme
AP Biology
only bacteria can digest
Ways to Digest Cellulose
 How can herbivores digest cellulose so well?

BACTERIA live in their digestive systems & help digest
cellulose-rich (grass) meals
 Humans can’t digest cellulose… so we poop it out.
I should have eaten
my fiber!
Regents Biology