Carbohydrates I Flashcards
What is the L- configuration?
L- Configuration: OH on left on penultimate Carbon
What is the D- configuration?
D-Configuration: OH on right on penultimate Carbon
What are enantiomers?
The L structure of glucose is the mirror image of D-glucose.
L form of named sugar is the mirror image of the same sugar, these are enantiomers
What are Diastereomers?
Same chemical type, size, but are non-mirror image
EX. D-glucose and D-Gulose
What are Epimers?
Diastereomers differing in configuration of one carbon only.
What carbons can be in close proximity in the cyclization of glucose?
Carbon 4 and Carbon 5 can be in close proximity of carbon 1
When this happens you make a ring structure.
What is an anomeric carbon?
The new Asymmetric carbon is called the anomeric carbon
What carbon is the new asymmetric carbon when cyclization occurs in sugars?
This will always be the carbon that was the carbonyl carbon
What carbons can be in close proximity in the cyclization of Fructose? and why is this different from glucose?
Carbon 5 and Carbon 6 can be in close proximity of carbon 2. This is because the carbonyl carbon is on Carbon 2. You can form a 5 or 6 member ring
What does the new asymmetric carbon acquire in cyclization of sugars?
The new asymmetric carbon has a new hydroxyl group
How do you know when the hydroxyl group is in alpha formation or beta formation?
If the hydroxyl group is down it’s in the alpha form
If the hydroxyl is up it’s in the beta form
What are anomers?
2 sugars that different only in the configuration of their anomeric carbon. (The anomeric carbon was the carbonyl carbon before so the –OH will be different for anomers)
What is the most common form of ribose? And why?
Beta-D-Ribofuranose
Most common form of ribose because that’s the form founds in ribonucleotides.
what is a 6 member ring called?
The 6 member ring is called pyranose
what is a 6 member ring called?
This is called furanose
What is a Galactosamine modified sugar?
Amine group added to C2
What is a N-acdetylglucosamine modified sugar?
Amine with acetyl group to C2
What is a Mannose-6-phosphate
modified sugar?
C6 with added Phosphate
What is a Fructose-1,6 bisphophate modified sugar?
C1 and C6 with added phosphate
What is a Glucuronic acid
modified sugar?
Oxidation of CH2OH to COO-
More polar and used to make things soluble.
What are glycosides?
Modified sugars that affect the hydroxyl in the anomeric carbon.
Ex. The anomeric carbon has a hydroxyl in the alpha position and the hydrogen is replaced by a methyl group. This prevents it from being linear.
What occurs when you modify a hydroxyl of an anomeric carbon.
Once you modify that hydroxyl in the anomeric carbon it gets stuck in the configuration its in.
What is Sorbitol (Glucitol)?
A Sugar Alcohol
-The aldehyde is reduced to an alcohol
What is the artificial sweetener sucralose?
Modified disaccharide
2 Sugar units
On right side Chloride on the C1 and C6
