Carbohydrate Structure and Function (CH4) Flashcards
Compounds that have the same chemical formula; these molecules differ from one another only in terms of the spatial arrangement of their component atoms.
Stereoisomers (aka Optical Isomers)
A special type of isomerism exists between stereoisomers that are nonidentical, non-superimposable mirror images of each other (such as D-glucose and L-glucose).
Enantiomers
Two sugars that are in the same family (both are either ketoses or aldoses and have the same number of carbons) that are not identical and are not mirror images of each other.
Diasterioisomers
A special subtype of diastereoisomers that differ in configuration at exactly one chiral center. The compounds are otherwise the same.
Epimers
How does one find the number of stereoisomers of a molecule with a common backbone?
- 2n
- n = the number of chrial carbons in the molecule
How are carbohydrates classified with absolute configuration?
All D-sugars have the hydroxide of their highest-numbered chiral center on the right and all L-sugars have that hydroxide on the left.
When two sugar molecules are the same but only differ in the configuration at the anomeric carbon, they are termed?
Anomers
Explain when an anomer is alpha vs beta.
- Alpha anomers have the OH group of C-1 trans to the CH2OH substituent (axial and down).
- Beta anomers have the OH group of C-1 cis to the CH2OH substituent (equatorial and up).
A six-membered sugar ring.
Pyranose
A five-membered sugar ring.
Furanose
This refers to the rearrangement of bonds in a compound; usually moving a hydrogen and forming a double bond.
Tautomerization
Sucrose
glucose-α-1,2-fructose
Maltose
glucose-α-1,4-glucose
Lactose
galactose-β-1,4-glucose
The main structural component of plant cell walls and main source of fiber in the human diet.
Cellulose
