BCHM-3050 Lecture Notes - Lecture 9: Copolymer, Ketose, Polymer
15 Jun 2018
School
Department
Course
Professor
Function of Carbs
Metabolism, storage and generation of energy
Generation of energy through catabolism
○
•
Molecular and cellular recognition
Ex. Immune system
○
Use part of polar head
○
•
Cell protection
Bacterial and plant cell walls
○
•
3Cell adhesion
Glycoproteins: made via sugar modifications which helps the
molecules bind together
○
•
Maintenance of biological structure
Cell frame works
○
•
Biological lubrications
Ex. Heparin
○
•
Glossary Terms
Monosaccharide: simple sugars
Monomer
○
3 to 9 carbons
○
•
Oligosaccharides: formed by linking several monosaccharides (2-4)
Linked by glycosidic bonds
○
•
Polysaccharides: form from multiple 4+ monomers
Polymers of monosaccharide
○
Homopolymer (same type of monomer) and heteropolymer
(different types of monomers)
○
•
Glycan: generic term for oligosacch. And polysacch.
•
Generic formula: (CH2O)n'
•
Aldose v Ketose
Aldose and ketose = two major classes of monosaccharides
•
Aldose: carbonyl on end of carbon chain
An aldehyde
○
•
Ketose: carbonyl on 2nd carbon
A ketone
○
•
Representative carbs
Glucose: monosacch
•
Maltose: disacch
•
Amylase: polysacch
Energy storage molecule
○
•
Triose (n=3)
Triose: monosaccharide with three carbons
•
D-glyceraldehyde (aldose)
Linear form contains aldehyde
○
•
Dihydroxyacetone (ketose)
Linear form contains ketone
○
•
(R v S) and (D v L) and (+ v -)
R v S: chirality of ONE chiral center
R = clockwise
○
S = counterclockwise
○
•
D v L: chirality of ALL chiral centers
Whole molecule
○
D = right
○
L = keft
○
•
'+ v -': optical rotation for specific isomer
•
Enantiomer: mirror image
•
Tetroses (n = 4)
Tetroses: monosaccharide with four carbons
•
Compound with >1 chiral carbon = enantiomer OR diastereomer
Diastereomer: not mirror image
○
•
For sugars: D and L refer to configuration around the chiral carbon
farthest from the carbonyl carbon
•
Erythrulose
Keto form of tetrose
•
Has ONE chiral carbon instead of two
•
Stereochemical relationship of aldoses and ketoses
The position of hydroxyl groups = very important
•
In aldoses:
For monomers with different numbers of carbons (even if they look
the same) they will have no relationship
○
Diastereomers are prevalent in molecules with 4+ carbon
○
•
For both ketoses and aldoses w same number of carbons = constitutional
isomers
Isomer with same molecular formula but different connections b/w
the atoms
○
•
Formation of 5 and 6 membered rings
Cyclization: create new chiral center
Anomers: isomers differing in configuration at the carbonyl carbon
○
New center: anomeric center
Alpha or beta
Alpha anomer: hydroxyl group below the ring
•
Beta anomer: hydroxyl group above the ring
•
§
Almost always C #1
§
○
•
Furanose: five membered ring
•
Pyranose: six membered ring
•
Use beta anomers in beta form DNA bases
•
Mutarotation: the monosacch. Undergoing interconversion b/w alpha and
beta forms
Use open chain structure as intermediate
○
•
Cyclic structure = Haworth projection
•
Conformation isomers of beta- D- ribofuramase
Conformation isomer: molecule with same stereo configuration but differ
in 3D conformation
Bond rotation of ring atoms
○
•
Chair from: lowest energy/most stable
Favored
○
•
Stereochemistry results from the fact that the ring cant be planar
When planar the groups cant rotate
○
However Groups on ring cant rotate
○
•
Common hexoses
Aldoses: glucose, mannose and galactose
•
Ketose: fructose
Anomer center = #2
○
•
Glucose and mannose: epimers
Epimers: cyclical diastereomers with different Stereochem about a
carbon other than the anomeric carbon
○
Same with glucose and galactose
NOT the same with galactose and mannose
§
○
•
Phosphate esters
Phosphate esters = participants in metabolic pathways
Very acidic
○
•
G1P: intermediate to the formation of glycogen and starch in mammals
•
Sugar phosphates: important intermediate in metabolism
Activated compound in synthesis
Ex. Glycolysis
§
○
•
Oxidation and reduction of Monosacch.
Oxidation of monosaccharides proceed in several ways depending on
oxidizing agent
•
Formation of lactone
Occurs via oxidation of gluconic acid
•
Oxidation at the carbon #1 forms aldonic acid
Equilibrium = lactone form
○
The aldehyde becomes carboxylic acid and then to lactone
○
•
All of this occurs with "reducing sugars"
Being oxidized so it is reducing something
○
Sugars with free anomeric aldol or hemi-acetal group
Basically need free -OH group
§
○
•
Reduction of sugar carbonyl = alditol
ALL OH functional groups are present
○
Reduce glucose = D-glucitol aka sorbito
○
•
Glycosides
Elimination of water b/w hydroxyl group of the anomeric carbon of cyclic
saccharide and hydroxyl group of another compound yields O-glycoside
New formed bond = glycosidic bond
○
•
Found in plant and animal tissues
•
Naming and writing of Disaccharide
Four features:
Sugar monomer and their stereochemistry
Epimer combo
§
○
Carbons involved in the linkage (#-#)
○
Order of sugars
If they are two different kinds
§
Note: a sugar is reducing
§
Free anomeric carbon can undergo oxidation
§
○
Configuration of anomeric carbon (alpha and beta)
Left monomer determines glycosidic linkage
§
○
•
Writing
Sequence is written starting w nonreducing end at left using abbreviation 1.
Anomeric and enantiomeric forms are designated by prefixes (ex.alpha-D)2.
Ring configuration indicated by suffix (ex. p for pyranose and f for
furanose)
3.
Atoms that form glycosidic bond are indicated via numbers in parentheses
(1->4)
4.
Monosaccharide => polysaccharide
Glycosidic bond: fall into two categories
Alpha
○
Beta
○
•
Biosynthesis of oligosacch and polysacch
Example rxn: formation of lactose using beta (1->4) link
The change of free energy is not favorable (+15)
Activation energy is needed
○
•
Slap on some phosphate!
•
Energy storage Polysacch.
Starch: plants
Amylopectin
○
Polyglucosepolymer
○
Amylose
Has helix with large interior core and is stabilized by H bonds
§
○
Cellulose: linear polyglucose polymer with beta (1-4) linkages
○
•
Glycogen: animals
Like amylopectin
○
High molecular weight with short and more frequent branchpoints
○
•
Chitin
Homopolymer of NAG
Derivatized form of cellulose
○
•
Component of exoskeleton of arthropods
•
Comparable to collagen
Less elastic and more rigid
○
•
Glycosaminoglycans
Structure and nonstructural roles in vertebrates
•
Heparin: anticoagulant
Bind to antiprothrombin II
○
Inhibit blood clot
○
•
Hyaluronic acid
Abundant in synovial fluid of joints
○
Biological lubricant
○
•
Glycoproteins: N linked and O linked
Glycoproteins: modified proteins that are covalently attached to
oligosacch or polysacch chains
•
NAG: n linked
Amino acid: asparagine
○
Linked to amino
○
•
NAM: O linked
Amino acid: threonine
○
Linked to oxygen
○
•
Chapter 9: Carbs
Friday, June 8, 2018
3:38 PM
Function of Carbs
Metabolism, storage and generation of energy
Generation of energy through catabolism
○
•
Molecular and cellular recognition
Ex. Immune system
○
Use part of polar head
○
•
Cell protection
Bacterial and plant cell walls
○
•
3Cell adhesion
Glycoproteins: made via sugar modifications which helps the
molecules bind together
○
•
Maintenance of biological structure
Cell frame works
○
•
Biological lubrications
Ex. Heparin
○
•
Glossary Terms
Monosaccharide: simple sugars
Monomer
○
3 to 9 carbons
○
•
Oligosaccharides: formed by linking several monosaccharides (2-4)
Linked by glycosidic bonds
○
•
Polysaccharides: form from multiple 4+ monomers
Polymers of monosaccharide
○
Homopolymer (same type of monomer) and heteropolymer
(different types of monomers)
○
•
Glycan: generic term for oligosacch. And polysacch.
•
Generic formula: (CH2O)n'
•
Aldose v Ketose
Aldose and ketose = two major classes of monosaccharides
•
Aldose: carbonyl on end of carbon chain
An aldehyde
○
•
Ketose: carbonyl on 2nd carbon
A ketone
○
•
Representative carbs
Glucose: monosacch
•
Maltose: disacch
•
Amylase: polysacch
Energy storage molecule
○
•
Triose (n=3)
Triose: monosaccharide with three carbons
•
D-glyceraldehyde (aldose)
Linear form contains aldehyde
○
•
Dihydroxyacetone (ketose)
Linear form contains ketone
○
•
(R v S) and (D v L) and (+ v -)
R v S: chirality of ONE chiral center
R = clockwise
○
S = counterclockwise
○
•
D v L: chirality of ALL chiral centers
Whole molecule
○
D = right
○
L = keft
○
•
'+ v -': optical rotation for specific isomer
•
Enantiomer: mirror image
•
Tetroses (n = 4)
Tetroses: monosaccharide with four carbons
•
Compound with >1 chiral carbon = enantiomer OR diastereomer
Diastereomer: not mirror image
○
•
For sugars: D and L refer to configuration around the chiral carbon
farthest from the carbonyl carbon
•
Erythrulose
Keto form of tetrose
•
Has ONE chiral carbon instead of two
•
Stereochemical relationship of aldoses and ketoses
The position of hydroxyl groups = very important
•
In aldoses:
For monomers with different numbers of carbons (even if they look
the same) they will have no relationship
○
Diastereomers are prevalent in molecules with 4+ carbon
○
•
For both ketoses and aldoses w same number of carbons = constitutional
isomers
Isomer with same molecular formula but different connections b/w
the atoms
○
•
Formation of 5 and 6 membered rings
Cyclization: create new chiral center
Anomers: isomers differing in configuration at the carbonyl carbon
○
New center: anomeric center
Alpha or beta
Alpha anomer: hydroxyl group below the ring
•
Beta anomer: hydroxyl group above the ring
•
§
Almost always C #1
§
○
•
Furanose: five membered ring
•
Pyranose: six membered ring
•
Use beta anomers in beta form DNA bases
•
Mutarotation: the monosacch. Undergoing interconversion b/w alpha and
beta forms
Use open chain structure as intermediate
○
•
Cyclic structure = Haworth projection
•
Conformation isomers of beta- D- ribofuramase
Conformation isomer: molecule with same stereo configuration but differ
in 3D conformation
Bond rotation of ring atoms
○
•
Chair from: lowest energy/most stable
Favored
○
•
Stereochemistry results from the fact that the ring cant be planar
When planar the groups cant rotate
○
However Groups on ring cant rotate
○
•
Common hexoses
Aldoses: glucose, mannose and galactose
•
Ketose: fructose
Anomer center = #2
○
•
Glucose and mannose: epimers
Epimers: cyclical diastereomers with different Stereochem about a
carbon other than the anomeric carbon
○
Same with glucose and galactose
NOT the same with galactose and mannose
§
○
•
Phosphate esters
Phosphate esters = participants in metabolic pathways
Very acidic
○
•
G1P: intermediate to the formation of glycogen and starch in mammals
•
Sugar phosphates: important intermediate in metabolism
Activated compound in synthesis
Ex. Glycolysis
§
○
•
Oxidation and reduction of Monosacch.
Oxidation of monosaccharides proceed in several ways depending on
oxidizing agent
•
Formation of lactone
Occurs via oxidation of gluconic acid
•
Oxidation at the carbon #1 forms aldonic acid
Equilibrium = lactone form
○
The aldehyde becomes carboxylic acid and then to lactone
○
•
All of this occurs with "reducing sugars"
Being oxidized so it is reducing something
○
Sugars with free anomeric aldol or hemi-acetal group
Basically need free -OH group
§
○
•
Reduction of sugar carbonyl = alditol
ALL OH functional groups are present
○
Reduce glucose = D-glucitol aka sorbito
○
•
Glycosides
Elimination of water b/w hydroxyl group of the anomeric carbon of cyclic
saccharide and hydroxyl group of another compound yields O-glycoside
New formed bond = glycosidic bond
○
•
Found in plant and animal tissues
•
Naming and writing of Disaccharide
Four features:
Sugar monomer and their stereochemistry
Epimer combo
§
○
Carbons involved in the linkage (#-#)
○
Order of sugars
If they are two different kinds
§
Note: a sugar is reducing
§
Free anomeric carbon can undergo oxidation
§
○
Configuration of anomeric carbon (alpha and beta)
Left monomer determines glycosidic linkage
§
○
•
Writing
Sequence is written starting w nonreducing end at left using abbreviation 1.
Anomeric and enantiomeric forms are designated by prefixes (ex.alpha-D)2.
Ring configuration indicated by suffix (ex. p for pyranose and f for
furanose)
3.
Atoms that form glycosidic bond are indicated via numbers in parentheses
(1->4)
4.
Monosaccharide => polysaccharide
Glycosidic bond: fall into two categories
Alpha
○
Beta
○
•
Biosynthesis of oligosacch and polysacch
Example rxn: formation of lactose using beta (1->4) link
The change of free energy is not favorable (+15)
Activation energy is needed
○
•
Slap on some phosphate!
•
Energy storage Polysacch.
Starch: plants
Amylopectin
○
Polyglucosepolymer
○
Amylose
Has helix with large interior core and is stabilized by H bonds
§
○
Cellulose: linear polyglucose polymer with beta (1-4) linkages
○
•
Glycogen: animals
Like amylopectin
○
High molecular weight with short and more frequent branchpoints
○
•
Chitin
Homopolymer of NAG
Derivatized form of cellulose
○
•
Component of exoskeleton of arthropods
•
Comparable to collagen
Less elastic and more rigid
○
•
Glycosaminoglycans
Structure and nonstructural roles in vertebrates
•
Heparin: anticoagulant
Bind to antiprothrombin II
○
Inhibit blood clot
○
•
Hyaluronic acid
Abundant in synovial fluid of joints
○
Biological lubricant
○
•
Glycoproteins: N linked and O linked
Glycoproteins: modified proteins that are covalently attached to
oligosacch or polysacch chains
•
NAG: n linked
Amino acid: asparagine
○
Linked to amino
○
•
NAM: O linked
Amino acid: threonine
○
Linked to oxygen
○
•
Chapter 9: Carbs
Friday, June 8, 2018 3:38 PM
Document Summary
Glycoproteins: made via sugar modifications which helps the molecules bind together. Homopolymer (same type of monomer) and heteropolymer (different types of monomers) Aldose and ketose = two major classes of monosaccharides. Linear form contains ketone (r v s) and (d v l) and (+ v -) R v s: chirality of one chiral center. D v l: chirality of all chiral centers. "+ v -": optical rotation for specific isomer. Compound with >1 chiral carbon = enantiomer or diastereomer. For sugars: d and l refer to configuration around the chiral carbon farthest from the carbonyl carbon. The position of hydroxyl groups = very important. For monomers with different numbers of carbons (even if they look the same) they will have no relationship. Diastereomers are prevalent in molecules with 4+ carbon. For both ketoses and aldoses w same number of carbons = constitutional isomers. Isomer with same molecular formula but different connections b/w the atoms.
