Glucose Molecule
Macromolecules
• Carbohydrates, proteins, and nucleic acids are
polymers
• Polymers – long molecules made from building
blocks linked by covalent bonds
• Monomers – the building blocks to polymers
• Monomers are connected to form polymers by a
condensation reaction, or specifically a
dehydration synthesis, named because a water
molecule is produced.
• Polymers are broken down into monomers by
hydrolysis, water is added to break the bonds.
Dehydration Synthesis and Hydrolysis
Dehydration reactions
build macromolecules –
enzymes facilitate this
process
Hydrolysis breaks down
macromolecules; also
with the aid of enzymes.
Example – digestion of
food
Monomers to Polymers
• Polymers of living things are made from only
40 to 50 common monomers
• These monomers have the potential of
producing thousands of different
macromolecules
• These macromolecules are responsible for
the great diversity among individuals of a
species and even greater diversity from
species to species
Monomers to Polymers
Class
Monomers or
Subunits
Functions
Energy, raw materials,
Carbohydrates Monosaccharides energy storage, structural
compounds
Energy storage, cell
Glycerol and fatty
Lipids
membranes, steroids,
acids = fats
hormones
Enzymes, transport,
Proteins
Amino acids
movement, receptors,
defense, structure
Nucleic Acids
Nucleotides
Heredity, code for amino
acid sequence
Carbohydrates
• Include sugars and their polymers
• Monosaccharide – single sugar or simple
sugar (ex. glucose)
• Disaccharide – double sugar, formed by two
monosaccharides bonded together
(ex. sucrose – made from the
monosaccharides glucose and fructose)
• Polysaccharide – many monosaccharides
bonded together (ex. starch – long chain of
glucose molecules)
Monosaccharides
• Have the general molecular formula of (CH2O)n
• Example: glucose (C6H12O6) a source of
energy for cells
• Name of monosaccharides usually ends in
-ose
• Have a carbonyl group and multiple hydroxyl
groups
• Carbon skeleton ranges from 3 to 7 carbons
• The diversity of monosaccharides is due to the
arrangements of parts around the carbons
Monosaccharides
Disaccharides
• Joined by a glycosidic linkage, covalent bond
b/w two mono. by a dehydration reaction
Polysaccharides
• Formed from a few hundred to a few thousand
monosaccharides joined by a glycosidic
linkage
• Serve two main purposes: storage and
structure
Storage Polysaccharides
• Starch
– major storage polysaccharide in plants
– Made up of glucose monomers
– Source of stored energy
– Humans and other animals hydrolyze the starch
in potatoes and grains for a source of energy
• Glycogen
– storage polysaccharide in animals
– Stored mainly in the liver and muscle cells
– Reserves only last about 1 day in humans
Structural Polysaccharides
• Cellulose
– Major component in plant cell walls
– Made up of glucose monomers
– Differs from starch in the linkage of the glucose
monomers
– Many animals, including humans, are unable to
digest cellulose
• Chitin
– Makes up the exoskeletons of arthropods
– Hardens with the aid of calcium carbonate
– Also found in the cell walls of fungi
Cellulose