BIO.A.2.2.1: To explain how carbon is uniquely
suited to form biological macromolecules
Objective: To discuss the unique
properties of carbon
Warmup: What do you think of when
you hear the word organic ?
CARBON

Carbon’s atomic structure:
 How many electrons are
in carbon’s valence electron
level?
4
 Is carbon reactive?
Yes, it’s not full
 How many bonds can carbon
form?
4

Because carbon can form these bonds, it forms
covalent bonds with other carbon atoms to form a
variety of carbon backbones (skeletons).

Carbon backbones are drawn based on their chemical
formulas. For example, which carbon arrangement
above matches to:
 C6H12
straight chain
 C6H6
ring
 C6H14
branched

Organic molecules contain carbon attached to
hydrogen. Oxygen and nitrogen may also be in the
molecule.
Example: C6H12O6 and C18H34O3

Inorganic molecules contain carbon or hydrogen but
not both. They are usually described as being noncarbon based.
Example: H2O, NaCl, CO2

Using these definitions, identify the following
molecules as either organic (O) or inorganic (I)
C5H12
H3PO4
NaCl
HCl
NH3
CH4
C10H22
CO2
H2O
C3H8
=
=
=
=
=
=
=
=
=
=
O
I
I
I
I
O
O
I
I
O

Organic molecules also contain functional groups.
These groups are responsible for organic molecules
having specific properties.

Common examples are shown below:
Elements in each group:
oxygen, hydrogen
carbon, oxygen
oxygen, carbon, hydrogen
hydrogen, nitrogen
sulfur, hydrogen
1. In order for a molecule to be classified as organic, it
must contain hydrogen and ________.
A) fat
B) water
C) carbon
D) sugar
2. Atoms of what element form the backbone of large,
complex molecules such as sugars and fats?
A) Oxygen
B) Sodium
C) Carbon
D) Sulfur
3. Carbon atoms have four electrons in their outer shell.
This means that a single carbon atom can form up
to_______ bonds with other atoms.
A) two
B) four
C) six
D) eight
4. Why can carbon form chains, branches and rings?
A) Most organic compounds are ionic
B) It has four electrons in its outermost shell
C) It only bonds with hydrogen
D) Most organic compounds have functional
groups
5. Carbon is able to form diversity of organic molecules
because of carbon’s
A) Ability to bond with up to four other atoms.
B) Capacity to form single and double bonds.
C) Ability to bond together to form extensive
branched, unbranched and ring structures.
D) All of the choices are correct.

Large molecules in living things are called
macromolecules
 They are also referred to as polymers
 Each is composed of smaller subunits called
monomers

Four macromolecules in humans:
Macromolecule
(Polymer)
Monomer
Function
Example
Carbohydrate
Monosaccharide
Broken down
glucose
sucrose
starch
for chemical
energy
Compose plant
cell walls

Four macromolecules in humans:
Macromolecule
(Polymer)
Monomer
Lipid
Glycerol
& fatty acid
Function
Builds membranes
Broken down for
chemical energy
Example
Fats
Oils
Waxes

Four macromolecules in humans:
Macromolecule
(Polymer)
Monomer
Function
Example
Proteins
Amino acids
Controls chemical
reactions
Albumin
Many other jobs
Hemoglobin

Four macromolecules in humans:
Macromolecule
(Polymer)
Monomer
Function
Example
Nucleic acids
Nucleotides
Store genetic
information
DNA
Build proteins
RNA
https://www.youtube.com/watch?v=b7TdWLNhMtM

Building Polymers: dehydration synthesis (or
condensation)
 “de”
= remove
 “hydro” = water
https://www.youtube.com/watch?v=b7TdWLNhMtM

Building Polymers: dehydration synthesis (or
condensation)
 Example:
Glucose +
C6H6O6
+
Fructose  Sucrose + H2O
C6H6O6  C12H22O11 + H2O
 Each time a monomer is added to the chain, a H2O
molecule is released.
https://www.youtube.com/watch?v=b7TdWLNhMtM

Breaking Polymers: hydrolysis
 “hydro” = water
 “lysis”
= to break
https://www.youtube.com/watch?v=b7TdWLNhMtM

Breaking Polymers: hydrolysis
 Example:
Sucrose + H2O  Glucose + Fructose
C12H22O11 + H2O  C6H6O6
+
C6H6O6
 Bonds are broken in a polymer by adding an H2O
molecule to them.
1. Polymers form (breakdown into) monomers with the
consumption of which chemical compound?
A) ADP
B) Water
C) Ethane
D) Nitrogen
2. Polymers are formed from monomers with the removal
of what molecule?
A) ADP
B) Water
C) Ethane
D) Nitrogen
3. The diagram above shows a reaction that forms a
polymer from two monomers. What is this type of
reaction called?
A) Glycolysis
B) Hydrolysis
C) Photosynthesis
D) Dehydration synthesis (condensation)