Macromolecules
• Macromolecules are large, functional, carbon
based structures that serve specific functions
in living organisms.
– 4 basic types
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Carbohydrates
Lipids
Proteins
Nucleic Acids
Carbohydrates & Lipids
• 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.
Carbohydrates
• Carbohydrates are sugars.
– Used as the main source of energy in living things
• Sugars can be single units which are monosaccharides
(simple sugars), as disaccharides, or as long chains which
are polysaccharides.
• Monosaccharides (monos - single, sacchar - sugar)
– empirical formula of (CH2O)n
– Common forms… glucose, galactose, fructose
• Molecular formula C6H12O6
• Are isomers of each other… same formula but different arrangement
Synthesis of Carbohydrates
• Can be formed through a condensation reaction
– Each monosaccharide is added through the process of
dehydration synthesis forming a glycosidic linkage
• Removal of a water molecule when forming a bond
• Can be separated through hydrolysis
– Addition of water to break the bond
Common Sugars
• Common Disaccharides
– Maltose… glucose + glucose
– Sucrose… glucose + fructose
– Lactose… glucose + galactose
• Common Polysaccharides
– Starch … plant storage for food
– Cellulose… rigid structural material in plants
• Not digestible in animals
– Glycogen… animal storage for food
• Lipids are macromolecules connected by ester
linkage (via dehydration synthesis) between a
glycerol molecule and 3 fatty acid chains
(triglyceride or triacylglycerol).
• Glycerol
– 3 carbon alcohol molecule
• each carbon is attached to a hydroxyl (-OH)
functional group
• Fatty acid
– chain of about 16 - 28 carbon atoms
– has a carboxyl g roup on the side that attaches
to the glycerol
– very hydrophobic (water hater!)
– a fatty acid with no double bonds is said to be
saturated
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most animal fats (lard, butter,...)
solid at room temp
chains can tightly pack (linear in shape)
a diet rich in saturated fats leads to atherosclerosis
…hardening of the arteries
– a fatty acid with at least one double bonds is
said to be unsaturated
Lipids
Lipids
• Are used for…
– Storage of energy…
• Storage of fat in humans is called adipose
– Cell membranes
• Phospholipid bilayer
– Chemical messengers… steroids
– Insulation and shock absorption