4 Polymer Vs. Monomer Polymer: A large molecule made up of
identical or similar building blocks Ex. Polysaccaride Starches
Monomer: the building block that is used to make polymers
Glucose
Slide 6
Carbohydrates Carbohydrates are composed of C, H, O Most names
for sugars end in ose CH 2 O (Empirical Formula) (CH 2 O) C 6 H 12
O 6 Contains a Carbonyl (C=O) & many Hydroxyl (OH) Function:
Energy & Storage ex: sugars, starches, cellulose, chitin C 6 H
12 O 6 (CH 2 O) x
Biological function of monosaccharides ENERGY!!!! Key parts of
other molecules (e.g. nucleic acids, ATP) Monomers for
Disaccharides & Polysaccharides. They form polymers in
dehydration reactions.
Slide 9
Classifying Monosaccharides Monosaccharides are uniquely
identified based on: The location of the carbonyl carbon in the
straight chain form The number of carbons present The spatial
arrangement of carbons
Slide 10
Sugar structure 5C & 6C sugars form rings in solution Where
do you find solutions in biology? In cells!
Slide 11
Identifying monosaccharides The arrangement of the OH group on
the #1 carbon does not matter when naming sugars. The location of
the other groups on the 2,3,4, and 5 carbons does matter.
alpha-glucosebeta-glucose
Slide 12
C CC C C C 1' 2'3' 4' 5' 6' O energy stored in C-C bonds
Carbons are numbered
Slide 13
Carbon Skeleton 3-7 Carbons long Classified by number of
carbons 6C = hexose (glucose) 5C = pentose (ribose) 3C = triose
(glyceraldehyde) OH H H HO CH 2 OH H H H OH O Glucose H OH HO O H H
H Ribose CH 2 OH Glyceraldehyde H H H H OH O C C C 653
Slide 14
Functional groups determine function Ketone Carbonyl in middle
Aldehyde Carbonyl at end
Polysaccharides Polymers of sugars costs little energy to build
Function: energy storage starch (plants) glycogen (animals) in
liver & muscles structure cellulose (plants) chitin (arthropods
& fungi)
Slide 22
Polysaccharides Polymers of sugars joined by glycosidic
linkages. Serve two main functions Storage- glycosidic linkages are
hydrolyzed to obtain monosaccharides as energy is needed.
Structural- make up the materials that are used to protect the
organism.
Slide 23
Glycosidic Bonds Chemical linkage between the monosaccharide
units of disaccharides, and polysaccharides, which is formed by the
removal of a molecule of water Condensation reaction Condensation
reaction Bond forms between the carbon-1 on one sugar and the
carbon-4 on the other.
Slide 24
& Glycosidic Bonds An -glycosidic bond- formed when the OH
group on carbon-1 is below the plane of the glucose ring A
-glycosidic bond is formed when it is above the plane. Ex.
Cellulose- formed of glucose molecules linked by 1-4 -glycosidic
bonds (Above plane) Ex. Starch- composed of 1-4 -glycosidic bonds
(Below plane ) in starch in cellulose
Slide 25
24 Polysaccharides- 100s to 1000s of monosaccharides Storage
PolysaccharidesStructural Polysaccharides Starch Plants Cellulose
Plants Glycogen Animals Chitin Animals-Insects Fungi
Slide 26
Structural Polysaccharides Key in forming the structure of an
organism. Most common structural polysaccharide is cellulose. Makes
up cell walls in plants Used to make paper Chitin Polymer of
glucose Forms via 1-4 glycosidic linkage.
Slide 27
Cellulose Most abundant organic compound on Earth herbivores
have evolved a mechanism to digest cellulose most carnivores have
not cellulose = undigestible rougha ge But it tastes like hay! Who
can live on this stuff?!
Slide 28
Cow can digest cellulose well; no need to eat other sugars
Gorilla cant digest cellulose well; must add another sugar source,
like fruit to diet
Slide 29
Helpful bacteria How can herbivores digest cellulose so well?
BACTERIA live in their digestive systems & help digest
cellulose-rich (grass) meals Rumen-Upper part of stomach
Slide 30
Digesting starch vs. cellulose starch easy to digest enzyme
cellulose hard to digest
Slide 31
Plant Storage Polysaccharides Starch is the main storage
polysaccharide- Found in two forms. Amylose- main storage
polysaccharide found in plants. 1-4 glycosidic linkage found in
glucose. Amylopectin- also in plants. Like starch with branching.
Branch occurs with a 1-6 glycosidic link.
Slide 32
Storage Polysaccharide in Animals Glycogen is the main storage
polysaccharide in animals. It is even more highly branched than
amylopectin. Stored primarily in muscle and liver cells and is used
when glucose stores are low.
Slide 33
Polysaccharide diversity Molecular structure determines
function isomers of glucose structure determines function in
starchin cellulose
Slide 34
Linear vs. branched polysaccharides starch (plant) glycogen
(animal) energy storage slow release fast release
Slide 35
Fig. 5-6 Glycogen Branched Starch Glycogen Amylose Chloroplast
Starch Unbranched Amylopectin Mitochondria Glycogen granules 0.5 m
1 m
Slide 36
Difference between starch and cellulose Starch production
involves 1-4 glycosidic linkage of -glucose monomers. Helical shape
Cellulose production involves 1-4 glycosidic linkage of -glucose
monomers Never branched, straight - Glycogen - Cellulose Does this
matter?
Slide 37
Fig. 5-7a (a) and glucose ring structures Glucose Glucose
Slide 38
Fig. 5-7bc (b) Starch: 14 linkage of glucose monomers (c)
Cellulose: 14 linkage of glucose monomers
Slide 39
Chitin Chitin is the structural polysaccharide in arthropods
Ex. insects, spiders, crustaceans, and fungi. Similar to cellulose,
but it has a slightly different monomer that is a derivative of
glucose
Slide 40
Fig. 5-10 The structure of the chitin monomer. (a) (b) (c)
Chitin forms the exoskeleton of arthropods. Chitin is used to make
a strong and flexible surgical thread.
Slide 41
YES, It matters! Cellulose has a much different structure than
starch. In storage polysaccharides, the polymer hydrogen bonds
mainly with itself to form helices (spirals) Ex. Glycogen In
structural polysaccharides, the polymer hydrogen bonds with other
polymer strands to form a strands that form thread like structures
Ex. Chitin & Cellulose
Slide 42
41 Starch vs. Cellulose Helix Sheet
Slide 43
IT REALLY MATTERS Animals lack the enzymes (cellular machinery)
to break down cellulose. Only a few bacteria and fungi can break
down cellulose.