Carbohydrates Flashcards
Structure of glucose
Hexose sugar: has 6C
Aldose sugar with its carbonyl group (c=o) located within C skeleton
In aq, c1 combines with c5 to for pyranose ring
Diff between a and b glucose ?
a: OH group on C1 positioned below the pyranose ring
B: OH group on C1 positioned above the pyranose ring
Describe 1,4 glycosylic bond formation
Condensation
Between C1 on one glucose and C4 on another glucose.
C1 lose H, C4 loses OH
How to break glycosidic bond ?
Hydrolysis
- dilutes avid boiled at 100 w specific enzymes
What is starch made of ?
Amylose and amylopectin
Amylose vs amylopectin
1. Bond
2. Monomers
3. Orientation of monomers
4. Shape
5. Function
6. Ease of hydrolysis
7. Solubility
- a 1,4-glycosidic bond
a 1,4- glycosidic bond and a 1,6- glycosidic bond - a glucose
- All in same orientation
- Unbranded coiled into helical shape
Branched to form compact rush shape - Storage fucntion in plants
- Easily hydrolysed due to lack of cross-linkages
- Insoluble
Cellulose
1. Bond
2. Monomers
3. Orientation of monomers
4. Shape
5. Function
6. Ease of hydrolysis
7. Solubility
- b 1,4- glycosidic bond
- B glucose
- Alternate glucose are rotated 180 to each other
- Straight chains
- Structural role in celll wall
- Has high tensile trench ue to crisslinkages
- Insoluble
Describe the structure of cellulose
Each cellulose chain consist of 10000 b glucose monomers, where alternate b glucose are rotated 180 to eave other.
B glucose monomers are joined by B 1,4-glycosidic bond forming straight chains.
OH groups projected in all directions allowing interchain H bonds to form between b glucose c
Chais, forming cellulose micelles
Further aggregate into L micro fibrils and the macro fibrils of cellulos
What does cross linking refer to ?
Interchain H bonds between OH groups of B glucose on different straight chains
Effects
- Allows for association into micro fibrils and macro fibrils for mechanical strength
- OH groups involved in H bonds hence not available to form H bonds with water thus is insoluble
Compare the osmotic effect of glucose glycogen and fats
Glucose > glycogen > fats
Glucose: small and soluble monosaccharide
Glycogen: large and insoluble polysaccharide
Fats: insoluble
Compare enerygy content of glucose glycogen and fats
Fats > glycogen > glucose
Fats store more energy than carbohydrates
Glycogen more than glucose cuz it’s branched and can store more glucose monomers
Define the term glycosidic bond
Covalent bond between 2 sugar molecules formed via a condensation reaction
