Carbohydrates Flashcards
which diagrams have D & L glucose ?
fischer projection
how to check for fischer projection for D & L configuration ?
2nd last C (at bottom) has OH on right side = D
on left = L
How are the dissacharides sucrose, maltose & lactose formd?
sucrose = glucose + fructose
matlose = 2 glucose
lactose = glucose + galactose
wht are the 2 polysaccharides of glucose?
starch, cellulose
name 2 pairs of epimers
D-glucose & D-galactose
glucose & mannose
erythrose & threose
epimer
same molecule with 1 bond rotation
how to determine α & β carbohydrate from chair conformation ?
α = when CH2OH (on C-6) & OH (on C-1) is in different plane
β = same plane
monosaccharide oxidation = ?
COOH (product)
mono reduction = ?
OH [alcohol] by NaBH4
mono esterification
COOR [ester]
What happens when aldehyde, ketone, & terminal hydroxy group are oxidized?
COOH forms
what happens in the reduction of :
1️⃣glucose
2️⃣galactose
3️⃣mannose
4️⃣fructose
it forms:
1️⃣sorbitol
2️⃣dulcitol
3️⃣manittol
4️⃣mannitol + sorbitol
epimerization
forming 2 epimers
enolate ion
C=C-O(minus)
how to form a C-2 epimer of glucose
glucose ➡️ enolate ➡️ D-mannose
all same except C-2 OH position change
what happens in Enediol rearrangement to turn glucose ➡️ fructose ?
aldehyde ➡️ ketone at C-2
oligosaccharides
2 to 10 monosaccharide units
linked by glycosidic bonds
other names for glucose
dextrose / blood sugar
fructose common name
gruit sugar
sucrose common name
table sugar
Lactose common name
Milk sugar
chiral C
C atom bonded to 4 different groups
how are D & L molecules related?
They are stereoisomers and enantiomers to each other
what is same & different in D & L isomers
same molecular formula
same connectivity of atoms
differ only in the spatial arrangement
Which carbon is anomeric in Hawarth projection
C-1 (to the right of O in ring)
chiral C
Which carbon is anomeric in chair conformation ?
C-1 to the right
anomer
a special type of epimer of cyclic forms of carbohydrates that differ in configuration only at the anomeric carbon (C=O)(C-1)
