Carbohydrates: Structure and Properties Flashcards
Polyhydroxylated aldehydes and ketones and substances that yield such compounds upon hydolysis
Carbohydrates
_____ and _____ and substances that yield such compounds upon hydolysis
Polyhydroxylated aldehydes and ketones
Functions of Carbohydrates
energy source
structural framework
cells walls
nucleic acids and lipids and proteins
cell-to-cell recognition
Carbohydrates Major Classes
Single polyhydroxylated aldehyde or ketone unit
Monosaccharides (simple sugars)
Carbohydrates Major Classes
Consist of two monosaccharides linked together by a glycosidic bond
Disaccharides
Carbohydrates Major Classes
Made up of 3-10 monosaccharide units
Oligosaccharide
Carbohydrates Major Classes
Long chains of monosaccharide units
Polysaccharides
Monosaccharides
General formula:
Simplest would be those with
(CH2O)n
n = 3
Classifying monosaccharides based on
carbonyl group present and the number of carbon atoms
Classifying monosaccharides based on carbonyl group present
Aldose
Ketose
Classifying monosaccharides based on the number of carbon atoms
Triose
Tetrose
Pentose
Hexose
Heptose
All monosaccharides (except dihyroxyacetone) are optically active
Stereochemistry
All monosaccharides (except dihyroxyacetone) are
optically active
All monosaccharides (except _____) are optically active
dihyroxyacetone
No. of Stereoisomers = 2n
n = no. of
chiral centers
No. of Stereoisomers = 2n
For _______, n=1 2¹ = 2 stereoisomers
Aldotriose
No. of Stereoisomers = 2n
For _____, n= 2 2² = 4 stereoisomers
Aldotetrose
No. of Stereoisomers = 2n
For ______, n=3 2³ = 8 stereoisomers
Aldopentose
No. of Stereoisomers = 2n
For ________, n=4 2⁴ = 16 stereoiseomers
Aldohexose
Sugars that differ in configuration in only one carbon other than the penultimate carnbon
Epimers
-OH at anomeric C cis to -CH²OH
b - anomer
-OH at anomeric C trans to -CH²OH
a - anomer
Stereoisomers that differ in configuration at the anomeric carbon
Anomers
Conversion of anomers
Mutarotation
Anomers
All three structures are in _______ in aqueous soln’s
equilibrium
Sugars that are able to undergo oxidation coupled with a reduction of another substance
Reducing Sugars
Reducing Sugars
Sugars that are able to undergo _____ coupled with a _____ of another substance
oxidation
reduction
The anomeric carbon can react with an -OH of an alcohol to give a acetal called
glycoside
If the -OH is part of another monosaccharide, then the resulting glycoside is
disaccharide
Disaccharides
milk sugar
reducing
b-1, 4
Lactose
Disaccharides
sugar used in brewing beer
a-1, 4
reducing
Maltose
Disaccharides
common table sugar
a-1, b-2
non-reducing
Sucrose
Consider the open chain structure of
D-idose
Using Haworth structure, draw the b- and a- anomer of
D-idose
Draw a disaccharide made up of two a-anomers of D-idose linked through
a- 1, 6 glycosidic bond
Consist of ten to thousands of monosaccharide units
Polysaccharides
Polysaccharides
only one type of monosaccharide as repeating unit
homopolymes
Polysaccharides
more than one type of monosaccharide linked together
heteropolymers
Polysaccharides
major component of plant cell
Cellulose
Polysaccharides
major storage form of carbohydrates in plants
Starch
Polysaccharides
major storage form of carbohydrates in animals and fungi
Glycogen
Polysaccharides
Very similar with amylopectin in structure but with a higher degree of branching
Glycogen
N-containing polysaccharides which is the major component of exoskeletons of crustaceans (shrimp, crab, lobster etc)
Chitin
Polysaccharides
Major component of neural, connective and epithelial tissues that functions as shock absorber
Hyaluronic Acid
Formation of hemiacetals/hemiketals
Cyclic Structures
