 B4
– analyse the structure and function of
biological molecules in living systems carbohydrates
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Know formulas, chemical structure
List functions
Differentiate between monosaccharaides,
disaccharides and polysaccharides
Compare structure of cellulose, starch and
glycogen
Explain dehydration synthesis and hydrolysis
 Carbohydrates
contain C, H, and O in a ratio
of approximately 1:2:1
 2:1 ratio of H to O is the same is in H2O
 Contain repetitions of H-C-OH
 Monosaccharides
(Simple carbohydrates, or
sugars)
 Common monosaccharides have 5 or 6
carbons, usually arranged in a ring
 Hexoses
are 6-carbon monosaccharides
 Ex. Glucose, fructose, and galactose
 All
have the formula C6H12O6
 Differ in arrangement of atoms
 Structural
 Each
formula for glucose:
corner is a carbon atom
 Pentoses
are 5-Carbon monosaccharides
 Ex. Ribose
 Monosaccharides
combine in chains to form
polymers
 Two
monosaccharides combined = a
disaccharide
 Several
monosaccharides combined = a
polysaccharide
Disaccharides (2 monosaccharides)
 Ex. glucose + glucose  maltose
 Glucose
+ fructose  sucrose
 Glucose
+ galactose  lactose
 Tastes
not!
like sugar, looks like sugar, but it’s
Polysaccharides (complex
carbohydrates)
 Long, branched or
unbranched chains of
monosaccharides (up to
4000!)
 Common examples: starch,
glycogen, cellulose
 Differ in orientation of
bonds and degree of
branching
 Starch
 Glycogen
 Cellulose
 Glucose
and other monosaccharides are used
in cellular respiration, to provide energy for
cellular functions in all living organisms
 Glycogen is used for energy storage in
animals (found mainly in muscles and liver)
 Starch
is used for energy storage in plants (digested
by animals to provide energy from food)
 Cellulose
provides structure in plant cell walls
 Monosaccharides
combine to form polymers
by the process of condensation synthesis, or
dehydration synthesis
 A water molecule is given off for each bond
that forms
 Polysaccharides
are broken down into
monosaccharides by the process of hydrolysis
 One molecule of H2O is added for each bond that is
broken