carbohydrates Flashcards
How do you remember the structure of fructose?
Fructose is the ketose of glucose
How do you remember the structure of galactose?
Galactose is the C-4 epimer of glucose
Anomers
vary at the chirality of the most oxidized Carbon. The CYCLIC sugars vary at the chirality of the hemiacetal (aldoses) or hemiketal (ketoses)
Epimers
vary at the chirality at any one of the less oxidized carbons.
For anomers to exist what must form does the structure of a sugar need to be in?
cyclic
D-Glucose mnemonic
F** glucose
D-Mannose mnemonic
man uses his gun
D-Ribose mnemonic
Ribose is ALL RIGHT
epimers are what form of stereoisomer?
diastereomers
pyrans
six membered rings
furans
five membered rings
What does alpha anomer mean
technically means that the C1 OH is trans to the last carbon
What does beta anomer mean
technically means that the C1 OH is cis to the last carbon
The beta anomer has all its substituents equatorial in the chair conformation. What is the orientation of the C1, C3, C5 substituents of the alpha anomer?
axial, equatorial, equatorial
To go from linear to cyclic (six membered ring), which hydroxl group attacks the carbonyl group?
the last chiral carbon’s OH group attacks the carbonyl to form a hemiacetal
for aldohexoses to go from linear to furanose what is the mechanism?
the C4 OH group attacks the carbonyl group. the C4 has as its substituents C5 - CH2OH.
What is the mnemonic for remembering the conversion between Fisher projection and Haworth project? Which carbons does it apply to?
downright uplefting. It applies to the C2 - C4 (for aldohexoses that form pyranoses)
How to know if the glycosidic linkage is Alpha or beta?
If the C1 carbon of the linkage was alpha, then the linkage is alpha. If the C1 carbon of the linkage was beta, then the linkage was beta
What is the glycosidic linkage of sucrose? what are the two monosaccharides it is composed of?
alpha 1,2. composed of glucose (six membered) and fructose (5 membered ring)
dissacharride naming: the left sugar suffix is ? the right sugar’s suffix is? the ordering of sugars in the name?
left sugar suffix is -osyl
glycogen glycosidic linkage is?
alpha 1,4 linkage
branching is what
1,6
which polysaccharides have branching?
glycogen, amylopectin is the branched form of amylose which is the polymer of glucose that exists in plants
which polysaccharides do NOT have branching?
cellulose, amylose
every ___ residues glycogen has branch point
10
ketoses form what type of rings
5 membered rings
