• The individual pieces that make
them are called monomers.
–
–
–
–
2 monomers make a dimer
3 make a trimer ...
many together form a polymer
Roughly 40 - 50 different monomers
combine to make up the thousands
of different macromolecules
present in the cells.
• The 4 main classes are: lipids,
carbohydrates, proteins, and
nucleic acids.
– Can be formed through a
condensation reaction called
dehydration synthesis
– Can be separated through
hydrolysis
Macromolecules
Carbohydrates
• Carbohydrates are sugars. Sugars can be single units which
are monosaccharides (simple sugars), as disaccharides, or
as long chains which are polysaccharides.
• Each monosaccharide is added through the process of
dehydration synthesis forming a glycosidic linkage
Monosaccharides
• monos - single, sacchar – sugar… Often called simple sugars
– empirical formula of (CH2O)n
– Molecular formula C6H12O6 (Glucose)
• contains a carbonyl group and multiple hydroxyl groups
• end is suffix -ose
– aldose sugar…end carbonyl unit –
– ketose …middle carbonyl unit
• forms a hexagonal ring (hexose), other common rings are triose and
pentose
• Glucose, Galactose, & Fructose are common isomers
Common Disaccharides
• Disaccharides are formed
through the process of
dehydration synthesis.
– They are important as they are
small enough to be absorbed
intact through the small intestine
directly into the bloodstream
– Can be easily cleaved to release
glucose to support metabolism
• Starches are the polysaccharide storage
form of the simple sugars found in the
body
– Starch is stored by plants
– Glycogen is a branched polysaccharide
stored in the muscles of animals
• Both starch and glycogen are made
exclusively of glucose, in an alpha
arrangement, and can be used to release
glucose into the circulatory system when the
blood sugar drops
– Cellulose is a structural polysaccharide
much like starch but the orientation is a
beta pleat causing a more condensed
packaging that gives strength, support,
and makes the molecule indigestible to
most organisms
– Chitin is a structural polysaccharide
produced by arthropods to build
exoskeletons
Starches
• Hydrophobic molecules
formed by dehydration
synthesis creating ester
linkage
– Made of glycerol (3C
alcohol) and fatty acids
(long hydrocarbon chains)
– Triglyceride is the most
common form consisting of
a glycerol and 3 fatty acids
Lipids (fats)
•
•
•
A saturated fat has fatty acids containing no
double bonds…it is holding as many H as
possible
An unsaturated fat has at least 1 double bond
(monounsaturated)
A polyunsaturated fatty acid contains many
double bonds
Saturated vs
Unsaturated
Phospholipids and Steroids
• Phospholipids are a
major component of
cell walls.
– Are a diglyceride with
a phosphate molecule
creating a hydrophilic
and hydrophobic end
• A steroid is a
derivative of
cholesterol and is
used as a chemical
messenger in animals