Carbohydrates Flashcards
Are polyhydroxy aldehydes and ketones
Carbohydrates
Are simple sugars with 3 to 7 carbons in chain, with carbonyl at either terminal carbon or the carbon adjacent to it
Monosaccharides
Triose which is an intermediate on fructose metabolism
Glyceraldehyde
Tetrose found in blood and cartilage tissue
Erythrose
Pentose found in cells mitochondria and the sugar in RNA
Ribose
Main source of fuel in cell
Glucose
Hexose that can enter glycolysis and produce intermediates for Cellular respiration
Fructose
Examples of Pentoses
Ribose
Arabinose
Xylose
Lyxose
Examples of Hexoses
Allose
Altrose
Glucose
Mannose
Gulose
Idose
Galactose
Talose
Naturally occuring sygars are _____.
D-sugars
Monosaccharide categorized based on
A. Functional group present
B. Total number of OH
C. Number of carbon in exoskeleton
D. Number of Oh at the right position
AC
DL configuration based on _____
Dextro-Levo- based on ____
RS based on ______
Structure
Optical rotation
Cahn-ingold-Prelog Priority
_____ if OH farthest from carbonyl group is at the right
_____ if OH farthest from carbonyl group is at the left
D-sugars
L- sugars
Of all aldohexoses, ___ and ___ are common in nature. With ____ as the most abundant.
Glucose, Galactose
Glucose
____ comes from hydrolysis of starch and cellulose, while ____ comes from hydrolysis of fruit pectins
Glucose
Galactose
Diastereoisomers that differ in configuration around one stereogenic center only
Epimers
Epimeric pair that differ at C4
Galactose-glucose
Epimeric pair that differ at C2
Glucose-mannose
The OH and C=O groups can undergo intramolecular cyclization to form _____
Hemiacetals
Intramolecular cyclization results in formation of a new stereogenic center, called _____
Anomeric carbon
Cyclic hemiacetals of sugars sre drawn using
Haworth projections
_____ with only one anomeric carbon with different configuration
Diastereoisomers
Each cyclic hemiacetal can be isolated and crystallized separately, but when any one compound is placed in solution, an equilibrium mixture of all three forms is formed. This process is called _____
Mutarotation
Upon mutarotation, at equilibrium, the mixture consist of ____ of the alpha anomer, ___ of the beta anomer, and ___ of the acyclic hydroxy aldehyde (open chain form)
37%, 63%, trace amounts