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प्रश्न
Three cyclic structures of monosaccharides are given below which of these are anomers.
| (I) |  |
| (II) |  |
| (III) |  |
विकल्प
I and II
II and III
I and III
III is anomer of I and II
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उत्तर
I and II
Explanation:
This behaviour could not be explained by the open-chain structure (I) for glucose. It was proposed that one of the –OH groups may add to the –CHO group and form a cyclic hemiacetal structure. It was found that glucose forms a six-membered ring in which –OH at C – 5 is involved in ring formation. This explains the absence of –CHO group and also existence of glucose in two forms as shown below.
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संबंधित प्रश्न
Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.
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The following molecule is called as:
\[\begin{array}{cc}
\ce{CHO}\phantom{..}\\
|\phantom{......}\\
\ce{(CHOH)4}\\
|\phantom{......}\\
\ce{CH2OH}
\end{array}\]
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(i) Ribose
(ii) Glucose
(iii) Fructose
(iv) Galactose
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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
