Carbohydrates (part of the aldehyde & ketone test) Flashcards
Monosaccharides
Are simple sugars
What are the two types of simple sugar?
- Glucose
- Fructose
Glucose is what type of sugar?
Aldose (contains an aldehyde)
Fructose is what type of sugar?
Ketose (contains a ketone)
What are the two classifications of sugars (monosaccharides)?
- Aldoses
- Ketose
The suffix ______ use to identify a carbohydrate
“ose” (ex. glucose)
Aldoses contain what?
Aldehyde
Ketose contains what?
Ketones
Aldoses & ketose can be further classified based on the # of ________ they have using tri, tetr, pent, hex, etc
Carbon atoms (ex. an aldopentose) (glucose)
What are the 3 descriptions used to identify carbohydrates?
- Aldo or keto prefix- to indicate if the compound has aldehyde or ketone
- Tri, tetr, pent, hex, ect to indicate # of carbon
- “ose’ suffix to indicate it’s a carbohydrate
Carbohydrates a _________ when the last carbon in the fischer projection has the OH on the right
D- sugar (ex. D-glucose) (D usually stand for dextrorotatory)
Carbohydrates are ________ when the last carbon in the fischer projection has the OH on the left side
L-sugar (ex. L-glucose) (L usually stands for levorotatory)
L-sugars are ______ of D- sugars
Enantiomers
When an aldehyde or ketone reacts with 1 equivalent of alcohol it forms an __________
Hemiacetal (equilibrium doesn’t favor the unstable hemiacetal)
Whenever a carbonyl group & a hydroxyl group is present a in a compound then a stable ______ is formed
Cyclic hemiacetal (equilibrium favors the formation of the cyclic acetal (product))
Glucose can exist in a open or close ring form where in its closed cyclic form the ring is called a _________
Pyranose ring
Glucose (d-glucose) exicst mostly in its cyclic hemiacetal form which is called ____________
D- glucopyranose
The C1 position (the carbon attach to the carbonyl group) is called __________
Anomeric carbon
The stereoisomers of the pyranose ring is called __________
Anomers
The two anomers can be classified as _______ or _______
Alpha-anomer & beta anomer (the two anomer of D-glucopyranose is alpha- D-glucopyranose & beta-D-glucopyranose)
In the alpha -anomer the hydroxyl group at the anomeric position is _____ to the CH2OH group
Trans
In the beta anomer the hydroxyl group is _____ to the CH2OH group
Cis
A cyclic form of D-glucose will spend most of its time in a ___________ conformation
Chair conformation
Have to have the oxygen atom in the ______ right whether its in the Haworth or chair conformation
Upper right
In the chair conformation all substituents are on the _______ position
Equatorial
Hydroxy aldehydes can form ________ cyclic hemiacetals as well
Five-membered
Furanose
Is a 5-member ring that carbohydrates can form with oxygen atom in the ring (its a reaction between carbonyl group & hydroxyl at C5)
D-fructose can also be cyclized to give a pyranose (6 member ring) which results from a reaction between carbonyl group & hydroxyl at ____
C6