Chapter 15 Flashcards
Monosaccharides
Sugars that cannot be hydrolyzed into simpler carbohydrates
- Trioses
- Tetroses
- Pentoses
- Hexoses
- Heptoses
Disaccharides
Condensation products of two monosaccharide units
- Lactose
- Maltose
- Isomaltose
- Sucrose
- Trehalose
Polysaccharides
Condensation products of more than ten monosaccharide units (may be linear or branched polymers)
- Starches
- Dextrins
What is a functional group at the first carbon in an aldose?
Aldehyde
What is a functional group at the second carbon in a ketose?
Ketone
What does D refer to?
Dexter (on the right)
What does L refer to?
Laevus (on the left)
How do you recognize D based on the Fisher Projection?
When the penultimate (next to last) -OH group is on the right hand side.
How do you recognize L based on the Fisher Projection?
When the penultimate (next to last) _OH group is on the left hand side
Epimer
Isomers differing as a result of variations in configuration of the -OH & -H on carbon atom 2, 3, & 4 of glucose
How many chiral centers does a triose have?
1
How many chiral centers does a tetrose have?
2
How many chiral centers does a pentose have?
3
How many chiral centers does a hexose have?
4
If a molecule has 4 chiral centers, how many stereoisomers will it have?
Maximum of 16
D-isomers of aldo triose
- D-Glycerose (D-Glyceraldehyde)
D-isomers of aldo tetrose
- D-Erythrose
D-isomers of aldo pentose
- D-Lyxose
- D-Xylose
- D-Arabinose
- D-Ribose
D-isomers of aldo hexose
- D-Galactose
- D-Mannose
- D-Glucose
D-isomers of keto triose
- Dihydroxyacetone
D-isomers of keto pentose
- D-Xylulose
- D-Ribulose
D-isomers of keto hexose
- D-Fructose
D-isomers of keto heptose
- D-Sedoheptulose
Oxidation of the aldehyde group produces what functional group?
Carboxylic Acid
Reduction of the aldehyde group produces what functional group?
Primary Alcohol
Oxidation of a primary alcohol produces what functional group?
Aldehyde
Pyranose
A collective term for carbohydrates that have a chemical structure that includes a six-membered ring consisting of five carbon atoms and one oxygen atom
Furanose
A collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom
How is a pyranose formed in a monosaccharide?
- The pyranose ring is formed by the reaction of the hydroxyl group on carbon 5 (C-5) of a sugar with the aldehyde at carbon 1.
- This forms an intramolecular hemiacetal.
- -OH attacks -CHO
How is a furanose formed in a monosacchardie?
- The reaction is between the C-4 hydroxyl and the aldehyde
- -OH attacks -CHO
What functional group is present at the anomeric carbon in a monosaccharide when it exists in a pyranose form?
Hemiacetal
What functional group is formed in a disaccharide when two monosaccharides are condensed at their anomeric carbons?
Acetal*
Common Disaccharides
- Sucrose (glucosyl-fructose)
- Lactose (galactosyl-glucose)
- Maltose (glucosyl-glucose)
- Isomaltose
- Lactulose
- Trehalose (glucosyl-glucoside)
Acidic Polysaccharides
Polysaccharides that contain carboxyl groups, phosphate groups and/or sulfuric ester groups
Acidic Polysaccharide Examples
- Hyaluronic Acid*
- Chondroitin Sulfate*
- Heparin*
