Carbohydrates Flashcards
What is a Fischer projection?
Flattened 2D representation of a 3D molecule
How does a Fischer projection imagine a molecule?
Over a plane
In a Fischer projection, which way do horizontal bonds point?
Towards you
In a Fischer projection, which way do vertical bonds point?
Away from you
What are the two rotations allowed in a Fischer projection?
Rotating 180 degrees
Rotating three of the groups /
Where does the rotation of three of the groups happen?
Around a single bond
What are the three types of carbohydrates?
Monosaccharides
Disaccharides
Polysaccharides
What are monosaccharides?
Simple carbohydrates whos name ends in -ose
What do monosaccharides contain?
Either an aldehyde or a ketone
What are monosaccharides classified by?
The number of carbons
What type of structure can monosaccharides form?
Cyclic
How do monosaccharides form cyclic structures?
One OH- reacts with the carbonyl
What is the pyranose form?
6 membered cyclic structure
What is the anomeric carbon?
The carbon that was part of the carbonyl when the monosaccharide was in the straight chain form
What are the two major conformations that the pyranose form can have?
α-glucopyranose
β-glucopyranose
What are monosaccharides synthesised from?
Glyceraldehyde
What is the stereochemistry like in monosaccharides?
All D-carbohydrates have the same stereochemistry on the carbon furthest away from the carbonyl group as D-glyceraldehyde
The stereochemistry of which part of the molecule determine the saccharide?
-OH group
What type of bond is formed between the pyranose form and another monosaccharide?
Glycosidic
What is the name of the glycosidic bond based on?
The carbon number and anomer
What are the 2 ways that the glycosidic bonds can be arranged?
α
β
What are the three common disaccharides?
Sucrose
Maltose
Lactose
What is sucrose made up of?
Glucose
Fructose
What is maltose made up of?
Glucose
Glucose
What is lactose made up of?
Glucose
Galactose
What glycosidic bond is formed in sucrose?
α-1,2’-β linkage
What glycosidic bond is formed in maltose?
α-1,4’ linkage
What glycosidic bond is formed in lactose?
β-1,4’ linkage
When is maltose formed?
When starch is degraded by amylase