Chemistry of Carbon
Building Blocks of Life
AP Biology
2007-2008
Why study Carbon?
 All of life is built on carbon
 Cells
~72% H2O
 ~25% carbon compounds

 carbohydrates
 lipids
 proteins
 nucleic acids

AP Biology
~3% salts
 Na, Cl, K…
Chemistry of Life
 Organic chemistry is the study of
carbon compounds.

All living things have carbon in it!
Therefore…all living things are organic!
 C atoms are versatile building blocks
Very reactive atom.
 Outer most shell needs four more
electrons to be full or stable.
 Can form up to 4 stable covalent bonds

AP Biology
Let’s review the hierarchy of life
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Atom
Element
Molecule
Organelle
Cell
Tissue
Organ
Organ system
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
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Organism
Population
Community
Ecosystem
Biosphere
Whew! Glad you
didn’t forget that!
Did I mention this
will be on your
final exam in May?
We are adding 3 more!
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Atom
Element
Molecule
Monomers
Polymers
Macromolecule
Organelle
Cell
AP Biology
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Tissue
Organ
Organ system
Organism
Population
Community
Ecosystem
Biosphere
What is a monomer?
 What does the



prefix “mono”
mean?
ONE!
A single (one unit)
that are building
blocks of larger
molecules.
LEGO?
AP Biology
 LETTERS of the

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alphabet?
B
I
O
I
S
F
U
N
What is a polymer?
MONO+MONO+MONO+MONO=POLY
 LETTERS of the
 What does the


prefix “poly”
mean?
MANY!
Polymers are many
monomers joined
together
AP Biology

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alphabet?
Consider the previous
slide…
B
I
O
I
S
F
U
N
Polymers
 Long molecules built by linking repeating
building blocks in a chain

monomers
 Think individual legos!
 building blocks
 repeated small units

Held together by
covalent bonds
H 2O
HO
H HO
H
Dehydration synthesis
AP Biology
HO
H
Dehydration Synthesis or Condensation Reaction.
AP Biology
How to build a polymer
 Synthesis

You gotta
be open to
“bonding!
joins monomers by “taking” H2O out
 one monomer donates OH–
 other monomer donates H+
 together these form H2O

H 2O
requires energy & enzymes
HO
H
Dehydration synthesis
HO
H
enzyme
Condensation reaction
AP Biology
HO
H
Hydrolysis or Digestion
AP Biology
How to break down a polymer
Breaking up
is hard to do!
 Digestion

use H2O to breakdown polymers
 reverse of dehydration synthesis
 cleave off one monomer at a time
 H2O is split into H+ and OH–
 H+ & OH– attach to ends
requires enzymes
HO
 releases energy
H2O

enzyme
H
Hydrolysis
AP Biology
Digestion
HO
H
HO
H
What is a macromolecule?
 What does the prefix




“micro” mean?
SMALL
What does the prefix
“macro” mean?
LARGE!
Macromolecules are
many monomers and/or
polymers joined
together to form very
LARGE molecules.
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BIO + IS + FUN = BIO IS FUN
Letters of the alphabet represent
monomers.
Letters combine to make words represent
monomers combining to make polymers.
Combing words to make sentences
represent combining polymers to make
macromolecules!
AP Biology
The 4 Macromolecules
Building Blocks
of Life
AP Biology
2007-2008
Macromolecules
 Smaller organic molecules join together
to form larger molecules

macromolecules
 4 major classes of
macromolecules:
carbohydrates
 lipids
 proteins
 nucleic acids

AP Biology
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
Monomers: simple sugars (single
sugars) or monosacharride (prefix
mono=one & suffix saccharide = sugar ).
3 monosaccharides :

AP Biology
Glucose, fructose and galactose
sugar sugar sugar sugar sugar sugar sugar sugar
 Function:
Dietary energy
 raw materials

energy storage
 structural materials

 ex: sugars, starches, cellulose
AP Biology
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
More sugars!
 Disaccharides = 2 sugars
Sucrose,
 maltose,
 lactose

 Polysaccharides = many sugars
large polymers
 Starch
 Glycogen
 Cellulose
 Chitin
AP Biology

Building sugars
 Dehydration synthesis
monosaccharides
|
glucose
H2O
|
glucose
disaccharide
|
maltose
glycosidic linkage
AP Biology
The bond that joins
monosaccharides to create
polysaccharides
Building sugars
 Dehydration synthesis
monosaccharides
|
glucose
AP Biology
H2O
|
fructose
disaccharide
|
sucrose
(table sugar)
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
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
AP Biology
Helpful bacteria
 How can herbivores digest cellulose so well?

AP Biology
BACTERIA live in their digestive systems & help digest
cellulose-rich (grass) meals
EAT
Let’s build
X some
Carbohydrates!
AP Biology
2006-2007
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