NOTES: 2.3, part 1 - Macromolecules, Carbs & Lipids
The Chemistry of Carbon
 Why is CARBON so important to life?
 Living things are
and other elements (H, O, P, S, and N)
 Carbon atoms have
, allowing them to form strong covalent bonds with many
other elements
 Carbon has the ability to form millions of different
!
Polymer Principles
 POLYMER: large molecule consisting of many
 MONOMER:
molecule of a polymer
 MACROMOLECULE: large organic polymer
*Examples:
 POLYMERIZATION REACTIONS: chemical reactions that link 2 or more small molecules (
larger molecules (
) to form
)
 DEHYDRATION SYNTHESIS REACTIONS (or CONDENSATION): reactions during which
; an –H and and –OH are removed, producing
for each covalent linkage
 HYDROLYSIS: process that
water molecules
by the addition of
*Example:
CARBOHYDRATES
 Monosaccharides =
*are major nutrients for cells
*glucose is most common
*examples:
 Disaccharides =
*Also a source of energy
*Formed when 2 monosaccharides combine in a dehydration reaction;
*Examples:
 lactose (
):
 sucrose (
):
 Polysaccharides =
*formed by linking monomers in
Examples of energy storage polysaccharides:
-starch = glucose polymer in plants used for energy storage (
, etc.)
-glycogen = glucose polymer in animals stored in
vertebrates
of humans & other
Examples of structural support polysaccharides:
-cellulose = structural component of plant cell walls that
-chitin = forms exoskeletons of arthropods
LIPIDS
 insoluble in water (because they are
, or
)
 include: 1) Fats; 2) Phospholipids; 3) Steroids
1. FATS
 Composed of:
-A large proportion of C-H bonds and less oxygen than carbohydrates
(the nonpolar C-H bonds make the chain hydrophobic and insoluble in water)
- Example:
 during formation of a fat,
link fatty acids to glycerol
 Fatty acids may vary in # of carbon atoms (usually even #)
Saturated Fats
 no C-C double bonds in fatty acid tail
Unsaturated Fats
 one or more C-C double bonds in fatty acid tail
 __________________________________________
 __________________________________________
 __________________________________________
 __________________________________________
 e.g.:_______________________________________
 e.g.:______________________________________
Functions of Fats

(1 g of fat stores 2x as much energy as 1 g of carbohydrate)
 cushions vital organs in mammals (e.g.

)
(e.g. whales, seals)
2. PHOSPHOLIPIDS
 Important component of
3. STEROIDS
 Important component of some hormones
Cholesterol …
 is used to make many other steroids (including sex hormones in vertebrates)
 common component of cell membranes

(if have too much)