Organic Molecules
Bio
First Five
Compare and contrast
monosaccharides and
disaccharides.
Today’s Announcements
•
•
Cell Structure Unit Exam
• Corrections due no later than, Thursday,
February 27
Quiz: Carbohydrates & Lipids
• Friday, February 28
Table Groups
On a whiteboard, draw a Venn diagram to
compare and contrast monosaccharides and
disaccharides.
The many forms of glucose:
Straight chain(linear) form
(least common/stable)
α-Ring form
Alpha-ring
(“OH” group is
below the ring)
β-Ring form
Beta-ring
(“OH” group
is above the
ring)
Cyclic Structure of Glucose: Rotation
Straight open-chain glucose is so reactive that
almost all molecules quickly rearrange their
bonds to form two new structures. These
structures are six-membered rings like those
below. The beta version is more stable.
6
Other important monosaccharides
Fructose
•
•
Fruit sugar
E.g. high fructose
corn syrup
Ribose
•
Main component of
DNA and RNA
Galactose
•
•
Very important at the
cellular level
Found with glucose
(lactose) in dairy
products
GLUCOSE AND GALACTOSE
Slightly different structure= entirely different function
Glucose
Glucose
Combining monosaccharides to make…
DISACCHARIDES!
Maltose
Glucose
Fructose
Sucrose
Glucose
Galactose
Lactose
How are the two
monosaccharides joined?
Glycosidic Bond
However, to form this,
another molecule has
to be released. Can
you figure out what it
is?
H2O
6C
12H
6O
6C
12H
6O
12C
22H
11O
How are the two
monosaccharides joined?
Glycosidic Bond
+H2O
Partner Practice
Draw the monosaccharides below on a
whiteboard. Then, choose a disaccharide to
make by doing the reaction.
•
Monosaccharides:
• Fructose
• Glucose
• Galactose
•
Disaccharide:
• Sucrose
• Lactose
First Five
1.
What is the chemical formula for
glucose?
1.
Describe the differences between
the 3 forms of glucose.
Today’s Announcements
•
•
Cell Structure Unit Exam
• Corrections due no later than, Thursday,
February 27
Quiz: Carbohydrates & Lipids
• Friday, February 28 [Gold 1]
Individual Practice - Disaccharides
Can you…
Draw on the diagram where a glycosidic bond will form
and complete the diagram to show the disaccharide that
will be produced.
Individual Practice - Disaccharides
Can you…
Draw on the diagram where a glycosidic bond will form
and complete the diagram to show the disaccharide that
will be produced.
Polysaccharides
Polysaccharides are carbohydrate polymers made from many
linked monosaccharide monomers to form long chain-like
molecules.
glycogen
starch
polysaccharides
- made from glucose
monomers
cellulose
Polysaccharides Derived from Glucose
There are three main types of naturally
occurring polysaccharides. They are
cellulose, glycogen, and starch that are
of major importance.
Polysaccharides Derived from Glucose
Cellulose:
used to construct
cell walls in plants
Glycogen:
energy storage in
animals (e.g. in liver
and muscle tissues)
Starch:
energy storage
in plants
Polysaccharides
•
•
•
Functions: storage, structure, recognition
Starch and glycogen are storage molecules
Chitin and cellulose are structural molecules
Cell surface polysaccharides (polysaccharides
embedded in the cell surface membrane) are
recognition molecules
Starch
•
•
•
Starch is a plant storage polysaccharide
There are two forms of chains in starch
• amylose
• amylopectin
Most starch is 10-30% amylose and 7090% amylopectin
Starch
•
•
Amylose: compact, energetic spirals
of α-glucose molecules
Amylopectin: compact, branched,
energetic shapes of α-glucose
molecules
First Five
Describe the similarities and
differences between the two types
of chains in starch: amylose and
amylopectin.
Starch
Polysaccharides Derived from Glucose
Amylose has an unbranched structure.
28
Starch
Polysaccharides Derived from Glucose
Amylopectin has a branched structure.
29
Starch
Polysaccharides Derived from Glucose
An important reaction during digestion is the
hydrolysis of starchy foods as shown below.
starch  disaccharides  glucose
30
Glycogen
Polysaccharides Derived from Glucose
Glycogen is a carbohydrate polymer
that is stored in the liver and muscle
tissues in animals. It is the energystorage carbohydrate in animals.
31
Glycogen
Polysaccharides Derived from Glucose
Glycogen has a structure similar
to amylopectin (starch) except
that it is more highly branched
32
Cellulose
Polysaccharides Derived from Glucose
•
•
Cellulose is a plant structure molecule.
It is the most abundant organic molecule
•
•
found in all cell walls
breaks down very slowly in nature
Cellulose
Polysaccharides Derived from Glucose
•
Cellulose is formed from the β-glucose
molecules
•
•
β-glucose forms more hydrogen bonds
because of the orientation of the –OH
group on each glucose ring.
Both starch and glycogen are formed from
α-glucose molecules
Polysaccharides Derived from Glucose
Practice with Vocab: Frayer Models
In your notebook, Create a frayer model for the following
topics: Monosaccharide, Disaccharide, Polysaccharide
Definition:
Drawing of structure:
Characteristics:
(Write topic
here)
Example:
Polysaccharides Practice Problems
Begin in class.
Finish as homework.
•
DUE WEDNESDAY