Polysaccharides
• Macromolecule made up of monosaccharides
• formula: [Cx(H2O)y]n
• there are different types of bonds between two glucose molecules
ß-1,4-glycosidic bonds
• parallel arrangement
• Hydrogen bonds between chains
• > hold chains together as hydrogen bonds are really strong
I
α-1,4-glycosidic bonds
• form helices
• make structures easy accessible for enzyme for fast breakdown
M
Me Me Mm M
M
Homoglycan: made up of the same monosaccharide
Heteroglycan: made up from different monosaccharides M M
Function:
• energy storage
• Insoluble -> makes it a good for storage
if glucose would not be converted into storage polysaccharides, the glucose molecules
would be kept in the cell and disrupt the water balance, because the osmotic pressure
wouldn’t be kept stable. If there are a lot of glucose stored in the cell as free molecules,
the tonicity of the cell increases greatly inside the cell and water will defuse into the ·
cell to try and dilute the glucose making it swell and even burst.
• continuous energy supply
• the monosaccharides forming the polysaccharides are broken down one by one
allowing for manageable amounts of energy to be generated
• -> no blood sugar flunctuations
Glycogen
• principal storage of glucose in animals
• branched
• Made of α-glucose molecules
• contains two types of bonds
> α-1,4-glycosidic bonds -> bonds within chains
> α-1,6-glycosidic bond -> bonds between chains
comparison:
• the difference between glycogen and
amylopectin is the length of chains
• Glycogen chains are shorter for a
more compact store
, Starch
• found in plants only
• > form small grains
• Energy storage in plants
• polymer of -glucose joints together by glycosidic bonds
Type of starch:
Amylose Amylopectin
• 20% of the starch in a plant • 80% of the strach
• Helix due to α-1,4-glycosidic • Branched (every 20-30 monomers)
bonds only • has both α-1,4-glycosidic bonds and
• Long term storage α-1,6-glycosidic bonds
• compact due to helix structure • -> what makes the molecules branched
so hard for enzymes to access • Easy to access for enzymes due to large
due to smaller surface area surface area
........
Mit
88 -
8 - 8
-
88
⑳
I ...
88
⑨ ⑳ ....... . ...
I
W / -~
-
⑧
↳
L
...........
I
I v
-
Cellulose
• consists of -glucose monomers linked together tp form a polysaccharide
• Long chain
• β-1,4-glycosidic bonds
• Important component of the cell wall
• gives stabilization and strength to cell wall so plant can maintain structure -> prevents cell from
collapsing
• Very strong -> keeps cell turgid
• multiple cellulose chains form microfibrils which are hold together by many strong hydrogen bonds ->
bonds are what gives cellulose strength
• Many microfibrils form fibrils
Humans cannot digest cellulose, as the enzyme cellulose is not found in their bodies
• Macromolecule made up of monosaccharides
• formula: [Cx(H2O)y]n
• there are different types of bonds between two glucose molecules
ß-1,4-glycosidic bonds
• parallel arrangement
• Hydrogen bonds between chains
• > hold chains together as hydrogen bonds are really strong
I
α-1,4-glycosidic bonds
• form helices
• make structures easy accessible for enzyme for fast breakdown
M
Me Me Mm M
M
Homoglycan: made up of the same monosaccharide
Heteroglycan: made up from different monosaccharides M M
Function:
• energy storage
• Insoluble -> makes it a good for storage
if glucose would not be converted into storage polysaccharides, the glucose molecules
would be kept in the cell and disrupt the water balance, because the osmotic pressure
wouldn’t be kept stable. If there are a lot of glucose stored in the cell as free molecules,
the tonicity of the cell increases greatly inside the cell and water will defuse into the ·
cell to try and dilute the glucose making it swell and even burst.
• continuous energy supply
• the monosaccharides forming the polysaccharides are broken down one by one
allowing for manageable amounts of energy to be generated
• -> no blood sugar flunctuations
Glycogen
• principal storage of glucose in animals
• branched
• Made of α-glucose molecules
• contains two types of bonds
> α-1,4-glycosidic bonds -> bonds within chains
> α-1,6-glycosidic bond -> bonds between chains
comparison:
• the difference between glycogen and
amylopectin is the length of chains
• Glycogen chains are shorter for a
more compact store
, Starch
• found in plants only
• > form small grains
• Energy storage in plants
• polymer of -glucose joints together by glycosidic bonds
Type of starch:
Amylose Amylopectin
• 20% of the starch in a plant • 80% of the strach
• Helix due to α-1,4-glycosidic • Branched (every 20-30 monomers)
bonds only • has both α-1,4-glycosidic bonds and
• Long term storage α-1,6-glycosidic bonds
• compact due to helix structure • -> what makes the molecules branched
so hard for enzymes to access • Easy to access for enzymes due to large
due to smaller surface area surface area
........
Mit
88 -
8 - 8
-
88
⑳
I ...
88
⑨ ⑳ ....... . ...
I
W / -~
-
⑧
↳
L
...........
I
I v
-
Cellulose
• consists of -glucose monomers linked together tp form a polysaccharide
• Long chain
• β-1,4-glycosidic bonds
• Important component of the cell wall
• gives stabilization and strength to cell wall so plant can maintain structure -> prevents cell from
collapsing
• Very strong -> keeps cell turgid
• multiple cellulose chains form microfibrils which are hold together by many strong hydrogen bonds ->
bonds are what gives cellulose strength
• Many microfibrils form fibrils
Humans cannot digest cellulose, as the enzyme cellulose is not found in their bodies
