2.3 Carbohydrates and
Lipid Notes
IB Biology HL 1
Mrs. Peters
Fall 2014
U1. Monosaccharides
• Monosaccharides: simplest
carbohydrates
 simple sugars
 General formula (CH2O)n
 Major nutrients for cells
U1. Monosaccharides
• Monosaccharides:
 Linked using
condensation reaction
to disaccharides and
polysaccharides
 Ex: glucose, fructose,
galactose C6H12O6
U1. Monosaccharides
• Glucose: energy
source carried by the
blood to cells
• Galactose: used to
make milk
U1. Monosaccharides
• Fructose: used to
make fruit sweet
tasting and attractive
to animals
U1. Disaccharides
• Disaccharides:
• two monosaccharides
joined by a glycosidic
linkage (covalent bond
between
monosaccharides using
condensation)
 Ex: sucrose; maltose;
lactose
U1. Disaccharides
• Sucrose: glucose + fructose; carried by
phloem to transport energy to cells in
plants
U1. Disaccharides
• Maltose: 2 glucose; used in creating
starch
• Lactose: glucose + galactose; the sugar in
milk; source of energy
U1. Polysacchrides
• Polysaccharides: storage and structural
macromolecules made from a 40- over
1000 monosaccharides using the
condensation reaction
 Ex: starch, glycogen, cellulose
U1.Polysaccharides
Storage Polysaccharides
 Starch: found in plants, polymer made of long
chains glucose molecules that coil into a helical
shape, used for energy, compact shape and
insoluble
U1. Polysaccharides
Storage Polysaccharides
 **Glycogen: found in animals, a highly
branched polymer of glucose (short term
energy storage in liver and muscle cells),
insoluble
U1. Polysaccharides
Structural Polysaccharides
 Cellulose: used to make strong fibers; major
components on plant cell walls, long
straight chains of glucose
Bioweb.wku.edu
U2. Fatty Acids
Fatty Acid: a long
hydrocarbon “tail”
with a carboxyl
group at the head
end
U2. Fatty Acids
Fatty Acid Types:
Saturated: have no
double bonds in the
carbon chains
Unsaturated: have
double bonds in
carbon chains
U2. Fatty Acids
Fatty Acid Types:
Monounsaturated: have
one double bond in
carbon chains
Polyunsaturated: have
more than one double
bond in carbon chains
U3. Unsaturated Fatty Acids
Types of Unsaturated Fatty Acid Structures:
• cis-fatty acids: the hydrogen atoms
bonded to the two carbons of the double
bond are on the same side
U3. Unsaturated Fatty Acids
Types of Unsaturated Fatty Acid Structures:
•cis-fatty acids:
 Have a bend in the carbon chain
 Usually liquid at room temp – oils
 Have a lower melting point
U3. Unsaturated Fatty Acids
Types of Unsaturated Fatty Acid Structures:
• trans-fatty acids: the hydrogen atoms
bonded to the carbons in the double bond
are on the opposite sides.
U3. Unsaturated Fatty Acids
Types of Unsaturated Fatty Acid Structures:
•trans-fatty acids:
 Do not have a bend in the carbon chain
 Solid at room temperature – usually artificially
produced – margarine and partially
hydrogenated
U4. Triglycerides
Triglyceride:
Examples: fat in
adipose tissue, oil in
sunflower seeds
U4. Triglycerides
• Triglyceride: Consists
of three fatty acids
linked to glycerol by
condensation reactions
• Used as energy stores,
used during aerobic cell
respiration
• Examples: fat in adipose
tissue, oil in sunflower
seeds
Types of Lipids
Phospholipids:
major
components of
cell membranes
 Hydrophilic head
 Two fatty acid
tails
(hydrophobic)
Draw and label a
phospholipid
Carbohydrates vs. Lipids
Carbohydrates
• Easily digested, energy is
released more rapidly
• Soluble in water, easy to
transport
• Short term energy storage
• Stored as glycogen in
animals and starch in
plants
Lipids
• Twice as much energy per
gram than carbs, but harder
to break down (slow process)
• Non-polar, insoluble
• Long term energy storage
• Lipid storage is lighter for
same amount of carbs;
• stored as fat in animals
• Used for insulation and
buoyancy in animals
Time to Build!!
• Practice condensation and hydrolysis
reactions by building different types of
carbohydrates.
Time to build!!
• Practice condensation and hydrolysis
reactions by building different types of
lipids.
Role of Condensation and Hydrolysis
• Describe how condensation