(a) Name the branched chain component of starch.
(b) Ribose in RNA and deoxyribose in DNA differ in the structure around which carbon atom?
(c) How many peptide linkages are present in a tripeptide?
OR
Give three reactions of glucose which cannot be explained by its chain structure
(a) Amylopectin
Starch is the main storage polysaccharide of plants. Polysaccharides are carbohydrates made up of more than three sugar units. It is a polymer of 
- glucose and consists of two components— amylose and amylopectin. Amylopectin is the major brached chain polymer which consists of 
- D - glucose units.
Structure of amylopectin
(b) It differs around the second carbon atom.
(c) Two peptide linkages. Three peptide molecules are held by two peptide bonds in between first and second and second and the third molecule.
OR
Some reactions of glucose cannot be explained by its chain structure like -
•Glucose does not answer 2,4 - DNP test.
•It also doesn’t answer Schiff's reagent test.
•The pentaacetate group in glucose does not react with the hydroxylamine.
•Glucose also doesn’t form the hydrogen sulfite addition product with NaHSO3.
REASON: The first three reactions occur in spite of it having an aldehyde group. This happens because the aldehyde group in it is not a free group and is therefore proving that it is in a cyclic structure.
The last test indicates the absence of free - CHO group.
Couldn't generate an explanation.
Generated by AI. May contain inaccuracies — always verify with your textbook.
