enolisation of fructose followed by conversion to aldehyde by base
Explanation
Under alkaline conditions of the reagent,
fructose gets converted into a mixture of glucose
and mannose (Lobry de Bruyn van Ekenstein
rearrangement) both of which contain the –CHO
group and hence reduce Tollens’ reagent to give
silver mirror test.
2
AIPMT 2010 Prelims
MCQ (Single Correct Answer)
Which one of the following does not exhibit the phenomenon of mutaroation?
A
(+) Sucrose
B
(+) Lactose
C
(+) Maltose
D
($$-$$) Fructose
Explanation
Sucrose does not show mutarotation.
Only those sugars which have a free aldehyde or ketone group are capable
of showing mutarotation.
3
AIPMT 2009
MCQ (Single Correct Answer)
Which of the following hormones contains iodine?
A
Testosterone
B
Adrenaline
C
Thyroxine
D
Insulin
Explanation
Thyroxine contains iodine
4
AIPMT 2009
MCQ (Single Correct Answer)
The segment of DNA which acts as the instrumental manual for the synthesis of the protein is
A
ribose
B
gene
C
nucleoside
D
nucleotide
Explanation
The DNA sequence that codes for a specific
protein is called a Gene and thus every protein
in a cell has a corrosponding gene.
Questions Asked from Biomolecules
On those following papers in MCQ (Single Correct Answer)
Number in Brackets after Paper Indicates No. of Questions