Question

1. Diagram a representative structure of each of the following: a. Glycogen b. Amylose c. Amylopectin d. Cellulose e. Chitin 2. Using the diagrams above and your text, describe the chemical and physical similarities and differences among these molecules.

Answer 1

Sol:

1. The diagram representative structure each of the following is as follows:

a) The structure of the Glycogen is as follows: Cн-он H он H H Он сHа CHон сH,он O. O. H H OH OH он H H H Он Он он b) The structure of Amylose is as follows: CH-он CH-он OH OH n OH OH :8--r

с) The structure of Amylopectin is as follows: CH,он он а 41-6) Linkage он CH, он CH, он сH, CH,он ok он он он он он он он он In d) The structure of Cellulose is as follows: снон Он сңон H Он H Н он н Он Н н он Он -о- н сң он сңон он н т8 H бт, -т -т т.

e) The structure of the Chitin is as follows: o C-CH 0C-CH сн,он NH сн, он н NH он сH OH OH H H н ČH2OH NH Cн,он H H NH онс-сн, o-C-CH

2.

Similarities and differences in above drawn molecules  is as follows:

All are above mentioned is the example of the carbohydrates.

Carbohydrates are nothing but the hydroxy derivatives of the aldehydes and the ketones.

Polysaccharides are the are composed of the repeating units of the monosaccharide’s connected by the glycosidic bonds.

Polysaccharides are linear as well as branched polymers.

1. Glycogen:

Glycogen is also termed as the animal starch it present in liver, muscle and brain.

It is also present in a plant that does not has the chlorophyll for photosynthesis.

The structure of the glycogen is similar to that of the amylopectin with greater number of branches in the structure.

Glycogen is present in cells in the form of granules which has high molecular weight.

The complete hydrolysis of glycogen yields glucose.

2. Amylose:

The structure of the amylose is in the form of long unbranched chain in which 250-299 D-glucose units held by the alpha-(1-4) glycosidic linkages.

Amylose has some differences in properties than that of the amylopectin.

Amylose is soluble in water and it gives the blue color when diluted iodine solution is added in it.

3. Amylopectin:

The structure of the amylopectin has the branched chain with alpha-(1-6) glycosidic bonds at the point where branching initiated and also has the alpha-(1-4) linkages.

Amylopectin has some differences in properties than that of the amylose.

Amylose is insoluble in water and gives reddish color when iodine solution is added to it.

4. Cellulose :

Cellulose is a formed by the monomer unit in the form glucose. Due to this it is most abundant polysaccharides as compared to the other polysaccharides.

The cellulose is the very stable insoluble polysaccharides.

5. Chitin:

Chitin is a linear homopolysaccharide composed of N-acetyl glucosamine residues in b-linkage.

There is only difference in chitin and cellulose is the replacement of the hydroxyl group at C-2 with an amino group which is acetylated by acetyl group.

It is second most abundant polysaccharide in nature.