comparison between amylose & amylopectin

Question 1

what are the 3 similarities between amylose & amylopectin?

Answer 1

1. both amylose & amylopectin are coiled into helices, with most of the hydroxyl groups being capable of forming hydrogen bonds, which project into the interior of the chains
2. there are no hydrogen bond cross-linking between chains
3. there are 6 alpha-glucose residues for every complete turn of the helix

Question 2

what are the 3 differences between amylose & amylopectin?

Answer 2

1. type of structure
2. type of glycosidic bonds found
3. results from test for starch

Question 3

what is the difference between amylose & amylopectin in terms of the type of structure?

Answer 3

• amylose is unbranched,
• while amylopectin is branched

Question 4

what is the difference between amylose & amylopectin in terms of the type of glycosidic bonds found?

Answer 4

• in amylose, there is only 1 type of glycosidic bond found between the alpha glucose residues, with the glucose residues being linked by alpha (1-4) glycosidic bonds
• while in amylopectin, there are 2 types of glycosidic bonds found between the alpha glucose residues, with the glucose residues being linked by alpha (1-4) glycosidic bonds, & the branched points formed by alpha (1-6) glycosidic bonds

Question 5

what is the difference between amylose & amylopectin in terms of the results for the test for starch?

Answer 5

• amylose gives a dark blue colour with iodine in potassium iodine solution,
• whereas amylose gives a red-violet color with iodine in potassium iodine solution