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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
Give two evidences for presence of formyl group in glucose.
Glucose on oxidation with dilute nitric acid gives _______________
Draw the structure of α-D glucopyranose.
Classify the following carbohydrates into monosaccharide, disaccharide, oligosaccharide and polysaccharide:
glucose, cellulose, maltose, stachyose
What is the action of the following reagents on glucose?
hydroxylamine
Write a chemical reaction to convert glucose into glucose cyanohydrin.
Which of the following type of carbohydrates cannot be hydrolyzed?
From the following identify an example of disaccharides.
Which of the following monosaccharides is a tetrose sugar?
Which of the following carbohydrate is sweet to taste?
From the following identify the group that is exclusively consists of polysaccharides.
Identify the sugar having the molecular formula C6H1206.
Identify a non-reducing carbohydrate from the following.
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 |
Which reagent among the following is used to confirm presence of aldehydic carbonyl group in glucose?
One mole of a carbohydrate on hydrolysis gives one mole of glucose and one mole of galactose. Identify the carbohydrate.
Which element among the following is not present in saccharine?
\[\ce{CH3 - CH2 - CH2 - Br ->[Na][dry ether] A ->[Cl2] B}\]
Identify the product B in the above reaction.
Which one of the following is a carbohydrate but does NOT follow the general formula of carbohydrate?
Which one of the following is generally applicable to polysaccharides?
Which one of the following is Tetrose sugar?
Which one of the following is NOT soluble in water?
Which of the following statements is NOT true for glyceraldehyde?
Which of the following statement is NOT true about saccharic acid?
Which among the following reagents is used for conversion of glucose to glucoxime?
Identify the product Y in the following reaction.
\[\ce{Maltose ->[Hydrolysis] X ->[dil. HNO3][(excess)] Y}\]
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?
How many optical isomers are possible for a compound having four asymmetric carbon atoms?
Glucose is an aldose. Which one of the following reactions is not expected with glucose?
α-D (+) Glucose and β-D (+) glucose are ____________.
Classify the following into monosaccharides, oligosaccharides and polysaccharides.
Fructose
Classify the following into monosaccharides, oligosaccharides and polysaccharides.
Sucrose
Write the structure of α-D (+) glucopyranose.
The molecule of glucose is also called ______.
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 |
Starch and cellulose are compounds made up of many units of ______.
Identify the product obtained in the following conversion.
\[\ce{Glucose ->[(O)][Br2 water] Product}\]
\[\ce{CH2OH-CO-(CHOH)4-CH2OH}\] is an example of ______.
Describe the action of the following reagent on glucose:
dil. Nitric acid.
Explain the hydrolysis of sucrose.
Write the ring structure of glucose.
Why carbohydrates are generally optically active.
Why carbohydrates are generally optically active.
The linkage present in Lactose is ______.
Why are carbohydrates generally optically active?
Why carbohydrates are generally optically active?
Why carbohydrates are generally optically active.
\[\ce{CH2OH - CO - (CHOH)4 - CH2 OH}\] is an example of ______.
Why carbohydrates are generally optically active?
\[\ce{CH2OH-CO-(CHOH)4-CH2OH}\] is an example of ______.
Why carbohydrates are generally optically active?
Why carbohydrates are generally optically active.
Why carbohydrates are generally optically active.
What are the number of chiral carbon atoms and the number of formyl groups, respectively, present in ribose?
