carbohydrates Flashcards
classification of monosaccharides based on functional groups
and number of carbon atoms with examples
-aldose,>ketone
Trioses (3C)
-Glycerose
>Dihydroxyacetone
Tetroses (4C)
-Erythrose
>Erythrulose
Pentoses (5C)
-Ribose
>Ribulose
Hexoses (6C)
-Glucose
>Fructose
Explain anomerism in monosaccharides (including definition of anomeric
carbon)
Carbon derived from the carbonyl carbon compound (aldehyde/ketone)
α→-OH below the plane of the ring
β→-OH above the plane of the ring
Relate the reducing properties of sugars to Benedict’s test for their
detection and its clinical significance ***
reducing property is attributed to the free aldehyde or ketone grp of anomeric carbon
blue-sugar absent
green-0.5%sugar
yellow-1%sugar
orange-1.5% sugar
brick red 2% or more sugar
- Summarize the sources, composition and linkages for sucrose, lactose,
maltose and trehalose
Sucroseα1 → β2 glycosidic bond
Lactose β (1→4) glycosidic bond
Maltose α (1 → 4) glycosidic bond
Explain the reducing properties of disaccharides with reasons
▪ The reducing property is attributed to the free aldehyde or keto group of anomeric carbon.
▪Lactose and maltose – reducing sugar
▪Sucrose, trehalose - nonreducing sugar.
Epimers
Carbohydrates that differ in their configuration around specific c- atom other than the carbonyl c-atom.
* Glucose and galactose are epimers as they differ in their configuration around C4 C-atom. Similarly glucose and mannose are epimers as they differ around C2 C-atom.
Hyaluronic acid
D-glucuronic acid and N-acetyl D-glucosamine
-synovial fluid,vitreous humor
ezyme: hyaluronidase breaks the bond
Chondroitin sulfates
D-glucuronic acid and N-acetyl D-galactosamine 4- sulfate.
(bone, cartilage, tendons, heart, valves, skin, cornea
Heparin
N-sulfo D-glucosamine 6-sulfate and D-glucuronate 2-sulfate.
anticoagulant
Dermatan sulfate
L-iduronic acid .
in the skin.
Keratan sulfate
D-galactosamine and N-acetylglucosamine 6-sulfate.
in cartilage,cornea,CT
