Question

Choose the simplest aldehyde and ketone carbohydrate pair.

• A. glyceraldehyde and dihydroxyacetone
• B. ribose and ribulose
• C. erythrose and erythrulose
• D. glucose and fructose

Answer 1

The correct option is A glyceraldehyde and dihydroxyacetone

Monosaccharides are the simplest sugars which cannot be hydrolysed further.

Monosaccharides can be divided further based on the number of carbon atoms present into trioses (3C) which include glyceraldehyde (aldose) and dihydroxyacetone (ketose), tetroses (4C) which include erythrose (aldose) and erythrulose (ketose), pentoses (5C) which include ribose (aldose), deoxyribose and ribulose (ketose), hexoses (6C) which include glucose (aldose), fructose (ketose), galactose, etc.

If the structure contains a -CHO (aldehyde) group, it is referred to as aldose sugar and if it contains >C=O (keto) group, it is referred to as ketose sugar. Hence the simplest carbohydrate pairs are glyceraldehyde (aldose) and dihydroxyacetone (ketose).