2.03 Carbohydrates Flashcards
0
Q
Monomers or building blocks for all other classes of carbohydrates
A
Monososacharide
1
Q
General formula of carbohydrate
A
Cn(H2o)n
2
Q
Consisting of at least 3 carbons, each with a hydroxyl group except for one with carbonyl carbon
A
Monosaccharide
3
Q
Produced by joining two simple sugars by dehydration synthesis forming covalent bond
A
Disaccharide
4
Q
Produced by joining many monosaccharides together by many dehydration synthesis reactions forming a polymer molecules
A
Polysaccharides
5
Q
Used to measure blood glucose levels
Needs a few microliter of blood
A
Glucometer
6
Q
Most important monosaccharide in the biological system
Main source of energy
A
Glucose
7
Q
Very low glucose level
A
Hypoglycemia
8
Q
Very high glucose level
A
Hyperglycemia
9
Q
Two dimensional representation for showing the configuration of a stererocenter
A
Fischer projection
10
Q
Named after English chemist Sir Walter Haworth
Ring is drawn flat and viewed through its edge with the anomeric carbon on the right and the oxygen atom to the rear
A
Haworth Projection
11
Q
Cannot be hydrolyzed to a simpler compound
A
Monosaccharide
12
Q
Only two trioses
Found in glycolysis as breakdown products from fructose-1,6-bisphosphate
A
D-glyceraldehyde
Dihydroxyacetone
13
Q
With an aldehyde group at one end
A
Aldose
14
Q
Keto group found at nonterminal carbons
A
Ketose
15
Q
Two major forms have the same atomic composition but differ only in the position of the hydrogen and double bonds
A
Tautomer
16
Q
Carbon atoms that carry 4 different substituents or entities
A
Chiral or asymmetric carbon
17
Q
Molecules that have the same formula and the same structure, but have their atoms arranged in different ways in 3D space
A
Stereoisomers or isomers
18
Q
Isomers that are mirror images of one another but are non-superimposable on one another
A
Enantiomers
19
Q
Enantiomer designation
Right hand side
A
Dextrorotatory
20
Q
D-isomers
Constituent of ribonucleic acid
A
D-ribose
21
Q
Enantiomer designation
Left hand side
A
Levorototary
22
Q
D-isomers
Constituent of deoxyribonucleic acid
A
D-deoxyribose
23
Q
D-isomers
Milk
A
D-galactose
24
D-isomers
| Major energy source
D-glucose
25
D-isomers
| Intermediate in glycolysis
D-fructose
26
Isomers that are not mirror images of each other but with the same chemical composition
Diastereomers
27
Diastereomers that differ from each other in their configuration around one chiral c atom only
Epimers
28
Isomers that differ in configuration at the anomeric carbon
Anomers
29
Molecules with the same stereochemical configuration, but differing in 3-dimensional conformation
Conformational isomers
30
More stable conformation because of hydroxyl of carbon 1 and 2 are further removed and thus have less steric interference with the carbons 3,4 and 5
Chair conformation
31
How many stereoisomers does a 5-C aldose have?
8 (4 D-sugars and 4 L-sugars)
32
Pentose and hexose can cyclize as the ketone and aldehyde reacts with a distal OH forming either _______ or ________
Furanose
| Pyrannose
33
Derivatives of carbohydrates
```
Reducing sugar
Sugar alcohol
Amino sugar
Phosphorylation derivatives
Glycosides
```
34
With free anomeric carbons
| Undergoing redox reactions with the agents (peroxide, ferricyanide and some metals)
Reducing sugars
35
Lacks an aldehyde or ketone
| Reducing the carbonyl group of a sugar
Sugar alcohol
36
D-mannitol
Sugar alcohol
37
Sorbitol, sweetener
Sugar alcohol
38
An amino group substitutes for a hydroxyl
Amino sugar
39
Glucosamine
Amino sugar
40
May be esterifying a phosphate group to one of the hydroxyls
Phosphorylated derivatives
41
Formed by elimination of water between the anomeric hydroxyl of a cyclic monosaccharide and the hydroxyl group f another compound
Glycosides
42
Ouabain
| Amygdalin
Glycosides
43
Composed of two monosaccharides joined together by glycosidic bonds
Disaccharide
44
4 features that distinguish disaccharides from each other
Specific sugar monomer, stereoconfiguration
Carbons involved in the linkage/glycosidic bond
Order of the monomeric units
Anomeric configuration of the hydroxyl group in carbon 1 of each residue
45
Glucose + glucose
| Alpha (1->4) glycosidic linkage
Maltose
46
Glucose + fructose
| Alpha (1->2) glycosidic bond
Sucrose
47
Glucose + galactose
| Beta (1->4) glycosidic bond
Lactose
48
Polysaccharides with 3-20 monomeric units
Oligosaccharides
49
2 types of glycosidic linkages in oligosaccharide a
O-linked oligosaccharide chains of glycoproteins
| N-linked oligosaccharide chains of glycoproteins
50
Link to the protein via a glycosidic bond between a sugar residue and a serine or threonine OH
O-linked oligosaccharide chains
51
Tend to be complex and branched
| N-acetylglucosamine linked via N of asparagine residue
N-linked oligosaccharide chains of glycoproteins
52
Biological significance of oligosaccharides
Cell recognition and interaction
Enzyme regulation
Blood group antigens
53
Composed of many monomeric units
Polysaccharides
54
Polysaccharides of 1 type
Homopolysaccharide
55
Polysaccharide of multiple types
Heteropolysaccharide
56
Polymerization requires energy, meaning it is an ______ process
Anabolic
57
Properties that distinguish the various polysaccharides
Composition of monomeric unit
Linkages between the monomeric unit
Ways in which branches from the chains occur
58
Component sugar of cellulose
Glucose
59
Component sugar of amylose
Glucose
60
Component sugar of glycogen
Glucose
61
Component sugar of amylopectin
Glucose
62
Component sugar of agar
Galactose
63
Linear branched glucose polymer with alpha (1->4) linkages
Amylose
64
End glucose with an anomeric C1 that is not involved I the glycosidic bond
Reducing end
65
Glucose polymer with mainly alpha (1->4) linkages and alpha (1->6) linkages for branching parts
Amylopectin
66
Glucose polymer with alpha (1->6) linkages and is highly branched
Glycogen
67
Polymer of glucose with alpha (1->4) linkages and beta (1->6) linkages
Cellulose
68
Lubricant shock absorbent
| Water binding
Hyaluronic acid
69
D-glucoronic acid
| N-acetyl-D-glucosamine
Hyaluronic acid
70
Calcium accumulation
| Cartilage and bone formation
Chondroitin-4-sulfate
71
D-glucoronic acid
| N-acetyl-D-galactosamine-4-O-sulfate
Chondroitin-4-sulfate
72
Anticoagulant
Heparin
73
D-glucoronic acid
L-iduronic acid
N-sulfo-D-glucosamine
Heparin
74
Antibody
Gamma-globulin
75
N-acetyl-hexosamine
D-mannose
D-galactose
Gamma-globulin
76
Blood group specifically
Blood group substances
77
D-glucosamine
D-galactosamine
L-fucose
D-galactose
Blood group substance
78
Linear polymers of repeating disaccharides
| Monomeric unit tend to be modified with acidic groups, amino groups, sulfated
Glycosaminoglycan
79
Repeating disaccharide of glucoronate and N-acetyl-glucosamine
Hyaluronate
80
GAGs covalently linked to serine residues of specific core proteins
Class of complex macromolecules that contain ~95% carbohydrate
Proteoglycans
82
Carbohydrate chain in the proteoglycan is called
Glycosaminoglycan
83
6 classes of proteoglycan
```
chondroitin sulphate
dermatan sulphate
keratin sulphate
heparin sulphate
heparin
hyaluronate
```
84
Soluble glycosaminoglycan found in granules of mast cells
| Highly sulphated
Heparin
85
Inhibits clot formation by interacting with the protein antithrombin
Heparin
86
Lack polymers
Shock absorber
Cementing substances
Hyaluronate
87
Most abundant GAG
| Formation of bone, cornea
Chondroitin sulfate
88
Contains higher acelylated glucosamine than heparin
Heparan sulfate
89
More sulfated than heparin sulfates
Heparin
90
Synovial fluid, vitreous humor, ECM of loose connective tissue
Hyaluronate
91
Cartilage, bone, heart valves, cornea
Chrondroitin sulfate
92
Basement membrane, components of cell surfaces
Heparan sulfate
93
Component of intracellular granules of mast cells lining the arteries of the lungs, liver and skin
Heparin
94
Skin, blood vessels, heart valves
Dermatan sulfate
95
Cornea, bone, cartilage aggregated with chondroitin sulfate
Keratan sulfate
96
Function of carbohydrates
```
Energy source
Supporting structures
Component of nucleic acids DNA, RNA
Immune system
Signal transduction
```
97
Fructose, glucose, mannose and galactose have the same chemical formula C6H12O6; hence, they are all _____ of each other
Isomer
98
The structures of glucose and galactose differ only in the position of the hydroxyl group (-OH) at carbon 4; hence they are _______
C-4 epimers
99
The structures of glucose and mannose differ only in the position of the hydroxyl group (-OH) at carbon 2; hence they are _______
C-2 epimers
100
Galactose and mannose differ in the position of -OH groups at two carbons (2 and 4); hence, they are
Isomers
101
99% of the monosaccharides are in ______, in which the aldehyde (or keto) group has reacted with an alcohol group on the same sugar, making the carbonyl carbon assymetric
ring/cyclic form
102
Cyclization creates an anomeric carbon, generating ____ of the sugar
alpha and beta configurations
103
alpha-D-glucopyranose and beta-D-glucopyranose are both glucose but are _____ (differ in the projection of OH groups)
Anomers
104
The alpha and beta configurations are not mirror images. They are referred to as ___
Diastereomers
105
Sugars that can react with chromogenic agents causing the reagent to be reduced and colored, with the aldehyde group of the acyclic sugar becoming oxidized
Reducing sugar
106
Bonds that link sugars
Glycosidic bonds
107
Name the linkage.
| Lactose is synthesized by forming a glycosidic bond between carbon 1 of beta-galactose and carbon 4 of glucose.
Beta (1->4) glycosidic bond
108
If the group on the non-carbohydrate molecule to which the sugar is attached is an -NH2 group, the bond is called an _____
N-glycosidic link
109
If the group on the non-carbohydrate molecule to which the sugar is attached is hydroxyl group, the bond is called an _____
O-glycosidic link
110
All sugar-sugar glycosidic bonds are _____
O-type linkages
111
If a pair of sugars are mirror images (enantiomers), the two members of the pair are designated as _____
D- and L-sugars
112
Glucose, with four aymmetric carbon atoms, can form how many isomers?
16
113
Isomerism that is determined by its spatial relationship to the parent compound of the carbohydrates
D and L isomerism
114
Presence of asymmetric carbon atoms also confers ___ on the compound
Optical activity
115
In solution, glucose is often (dextrorotatory or levorotatory) and in the (furanose or pyranose)
Dextrorotatory
| Pyranose
116
Fructose has the same molecular formula as glucose but differs in its structures. There is a potential keto group in the anomeric carbon while in glucose, there is a potential aldehyde group in the anomeric carbon. This is an example of ______
Aldose-ketose isomerism
117
Formed by condensation between the hydroxyl group of the anomeric carbon of a monosaccharide, and a second compound that may or may not be another monosaccharide
Example is ouabain
Glycoside
118
Complex carbohydrates containing amino sugars and uronic acids
Glycosaminoglycans
119
GAGs + protein molecule
Preteoglycan
