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प्रश्न
Explain D and L configuration in sugars.
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उत्तर
D and L configuration in sugars:
- Conventionally (+)-glyceraldehyde is represented by the Fischer projection formula having –OH group attached to C-2 on the right side and this configuration is denoted by symbol ‘D’.
- Similarly, the configuration of (–) glyceraldehyde is denoted by the symbol ‘L’.
- All the compounds which can be correlated by a series of chemical reactions to (+)-glyceraldehyde are said to have D-configuration.
- And compounds which are chemically correlated to (–)-glyceraldehyde are said to have L-configuration. This is the system of the relative configuration of chiral compounds.
- A monosaccharide is assigned D/L configuration on the basis of the configuration of the lowest chiral carbon in its Fischer projection formula.
- Relative configuration of (+)-glucose with respect to (+)-glyceraldehyde can be drawn as follows:
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संबंधित प्रश्न
Glucose on oxidation with dilute nitric acid gives _______________
Explain the classification of carbohydrates with examples.
What is the action of the following reagents on glucose?
acetic anhydride
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Which of the following monosaccharides is a tetrose sugar?
Fructose is the fruit sugar and chemically it is ketohexose but it has a ______ rather than a ______.
Match the Column I and Column II select the correct option.
| Column I | Column II | ||
| i. | Monosaccharides | a. | Stored energy in animals |
| ii. | Glycogen | b. | Polymer made from ß-glucose molecules |
| iii. | Cellulose | c. | Exoskeleton of arthropods |
| iv. | Chitin | d. | Building blocks of carbohydrates |
| e. | Plant hormone |
____________ do not give smaller sugar units on hydrolysis.
Identify the CORRECT combination.
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Identify the product B in the above reaction.
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Match the Column I with Column II and choose the correct answer from options below:
| Column I | Column II |
| A. Purine | 1. Glycogen |
| B. Pyrimidine | 2. Cellulose |
| C. Structural polysaccharide | 3. Glucagon |
| D. Storage polysaccharide | 4. Adenine |
| 5. Cytosine |
Identify the monosaccharide containing only one asymmetric carbon atom in its molecule.
Formation of gluconic acid from glucose by oxidation using Br2 water.
\[\ce{CH2OH - CO - (CHOH)4 - CH2OH}\] is an example of ______.
\[\ce{CH2OH-CO-(CHOH)4-CH2OH}\] is an example of ______.
Why carbohydrates are generally optically active.
Why carbohydrates are generally optically active.
Assign D/L configuration to the following monosaccharides:
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Write the Zwitter ion structure of alanine.
Why carbohydrates are generally optically active.
Why carbohydrates are generally optically active?
Why carbohydrates are generally optically active?
\[\ce{CH2OH - CO - (CHOH)4 - CH2OH}\] is an example of ______.
\[\ce{CH2OH - CO - (CHOH)4 - CH2OH}\] is an example of ______.
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