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प्रश्न
Give scientific reasons:
The disaccharide sucrose gives negative Tollens test while the disaccharide maltose gives a positive Tollens test.
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उत्तर
- The structure of sucrose contains glycosidic linkage between C-1 of α-glucose and C-2 of β-fructose.
- Since the potential aldehyde and ketone groups of both the monosaccharide units are involved in the formation of the glycosidic bond (i.e., α, β-1,2- glycosidic bond), sucrose is a non-reducing sugar and gives negative Tollen’s test.
- The glycosidic bond in maltose is in between C-1 of one glucose ring and C-4 of the other (i.e., α -1,4-glycosidic linkage).
- The hemiacetal group at C-1 of the second ring is not involved in the glycosidic linkage. Hence, maltose is a reducing sugar and gives positive Tollen’s test.
APPEARS IN
संबंधित प्रश्न
\[\ce{CH2OH-CO-(CHOH)4-CH2OH}\] is an example of ______.
Give scientific reasons:
Hydrolysis of sucrose is called inversion.
Draw a neat diagram for the following:
Haworth formula of glucopyranose.
Glucose on oxidation with dilute nitric acid gives _______________
Write the name of the unit to which glucose unit is linked to from sucrose.
Explain the classification of carbohydrates with examples.
What is the action of the following reagents on glucose?
acetic anhydride
Draw the Haworth projection structure of the following.
α-D-(–)-Fructofuranose
Explain D and L configuration in sugars.
Draw the structure of the pyran.
Identify the given structure 'P' and 'Q'.
Formation of lactose by conden ation results in the release of how many molecules of water?
From the following which is a heteropolysaccharide?
Which among the following compounds is obtained when glucose reacts with hydrogen cyanide?
Identify a non-reducing carbohydrate from the following.
Chitin is a/an ______.
Which carbon atoms of α- D glucopyranose and β-D-fructofuranose respectively are linked together to form glycosidic linkage in sucrose?
Prolonged heating of glucose with hot HI results in the formation of ____________.
4-O-(α-D-Glucopyranosyl)-D-glucopyranose is ____________.
Identify the INCORRECT statement regarding glucose.
The general formula for polysaccharide is ____________.
Which one of the following is a carbohydrate but does NOT follow the general formula of carbohydrate?
Which one of the following is Tetrose sugar?
Which of the following statements is NOT true for glyceraldehyde?
Which of the following molecules reduces Fehling's solution?
What is the number of hydroxyl groups present in lactic acid?
Identify the number of secondary carbon atoms in glucose.
When 2 moles of stachyose is hydrolyzed, the number of moles of galactose obtained is ____________.
Which among the following reagents is used to confirm the presence of carbonyl group in glucose?
Which of the following statement is NOT true about saccharic acid?
Which among the following is a product of hydrolysis of one mole raffinose?
When one mole of lactose is hydrolysed, the hydrolysate contains ____________.
Which among the following observations suggests that glucose also exists in cyclic form?
The correct corresponding order of names of four aldoses with configuration given below Respectively is:
Glucose is an aldose. Which one of the following reactions is not expected with glucose?
α-D (+) Glucose and β-D (+) glucose are ____________.
Which of the following are epimers?
Classify the following into monosaccharides, oligosaccharides and polysaccharides.
Fructose
Write the structure of α-D (+) glucopyranose.
Is the following sugar, D-sugar or L-sugar?
Lactose is made of ______.
The two monosaccharides in a disaccharide are held together by ______ bonds.
Which one is a non-reducing commercial sugar?
\[\ce{CH2OH - CO - (CHOH)4 - CH2OH}\] is an example of ______.
\[\ce{CH2OH-CO-(CHOH)4-CH2OH}\] is an example of ______.
Assign D/L configuration to the following monosaccharides:
Describe the action of the following reagent on glucose:
dil. Nitric acid.
Explain the hydrolysis of sucrose.
Why carbohydrates are generally optically active.
Write the Zwitter ion structure of alanine.
\[\ce{CH2OH - CO - (CHOH)4 - CH2 OH}\] is an example of ______.
Why carbohydrates are generally optically active?
Given below are two statements.
Statement I - Lactose on hydrolysis converts into glucose and galactose.
Statement II - Galactose also plays same role as glucose in respiration.
In light of the above statements, select the correct option given below.
Which of the following is used to separate glucose and fructose from hydrolysate of sucrose?
