Three structures are given below in which two glucose units are linked.
Which of these linkages between glucose units are between C1 and C4 and which linkages are between C1 and C6?
(a) (i) is between C1 and C4, (ii) and (iii) are between C1 and C6
(b) (i) and (ii) are between C1 and C4, (iii) is between C1 and C6
(c) (i) and (iii) are between C1 and C4 (ii) is between C1 and C6
(d) (i) and (iii) are between C1 and C6, (ii) is between C1 and C4
Answer: (c) (i) and (iii) are between C1 and C4 (ii) is between C1 and C6
The numbering of glucose starts from the adjacent carbon of O- atom to the other carbon atom ending at last CH2OH group as shown below
In this way, numbers for the disaccharides can be done as