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प्रश्न
What are reducing sugars?
उत्तर १
Reducing sugars are carbohydrates that reduce Fehling’s solution and Tollen’s reagent. All monosaccharides and disaccharides, excluding sucrose, are reducing sugars.
उत्तर २
Carbohydrates which reduces Fehling’s solution to red precipitate of Cu20 or Tollen’s reagent to metallic Ag are called reducing sugars. All monosaccharides (both aldoses and ketoses) and disaccharides except sucrose are reducing sugars. Thus, D – (+) – glucose, D-(-)-fructose, D – (+) – maltose and D – (+) – lactose are reducing sugars
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संबंधित प्रश्न
What are the expected products of hydrolysis of lactose?
Write two main functions of carbohydrates in plants.
What are the hydrolysis products of sucrose
The following molecule is called as:
\[\begin{array}{cc}
\ce{CHO}\phantom{..}\\
|\phantom{......}\\
\ce{(CHOH)4}\\
|\phantom{......}\\
\ce{CH2OH}
\end{array}\]
Which of the following gives a positive Fehling solution test?
The two functional groups present in a typical carbohydrate are:
Monosaccharides usually contains ____________ carbon atoms.
Reducing sugars reduce ____________.
Glucose can’t be classified as ____________.
Which of the following reagent cannot distinguish between glucose and fructose?
The pair of compounds in which both the compounds give the positive test with Tollen’s reagent is:
Structure of a disaccharide formed by glucose and fructose is given below. Identify anomeric carbon atoms in monosaccharide units.
Which of the following monosaccharides are present as five membered cyclic structure (furanose structure)?
(i) Ribose
(ii) Glucose
(iii) Fructose
(iv) Galactose
Name the sugar present in milk. How many monosaccharide units are present in it? What are such oligosaccharides called?
Monosaccharides contain carbonyl group hence are classified, as aldose or ketose. The number of carbon atoms present in the monosaccharide molecule are also considered for classification. In which class of monosaccharide will you place fructose?
Which monosaccharide units are present in starch, cellulose and glucose and which linkages link these units?
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
| Carbohydrates are optically active polyhydroxy aldehydes and ketones. They are also called saccharides. All those carbohydrates which reduce Fehling's solution and Tollen's reagent are referred to as reducing sugars. Glucose, the most important source of energy for mammals, is obtained by the hydrolysis of starch. Vitamins are accessory food factors required in the diet. Proteins are the polymers of α-amino acids and perform various structural and dynamic functions in the organisms. Deficiency of vitamins leads to many diseases. |
Answer the following:
(a) The penta-acetate of glucose does not react with Hydroxylamine. What does it indicate? (1)
(b) Why cannot vitamin C be stored in our body? (1)
(c) Define the following as related to proteins: (2)
- Peptide linkage
- Denaturation
OR
(c) Define the following as related to carbohydrates: (2)
- Anomers
- Glycosidic linkage
