The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in alpha -anomeric form Choose the correct answer from the options given below:

The specific carbohydrate residue present across backbone units in DNA molecules is beta-2-deoxy-D-ribose. Its spatial parameters satisfy the following conditions: - It is a 5-carbon pentose sugars skeleton structure (A). - It maintains a canonical D configuration pathway sequence (C). - When localized in free, open unlinked molecular solutions, it standardly functions as a reducing carbohydrate assembly agent (D). - It exists predominantly in a furanose cycle form inside DNA, rather than a pyranose ring. Ribose in nucleic acids occurs primarily as a five-membered furanose ring configuration system. Class 12 Chemistry: Biomolecules

The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in alpha -anomeric form Choose the correct answer

The specific carbohydrate residue present across backbone units in DNA molecules is beta-2-deoxy-D-ribose. Its spatial parameters satisfy the following conditions: - It is a 5-carbon pentose sugars skeleton structure (A). - It maintains a canonical D configuration pathway sequence (C). - When localized in free, open unlinked molecular solutions, it standardly functions as a reducing carbohydrate assembly agent (D). - It exists predominantly in a furanose cycle form inside DNA, rather than a pyra

The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in alpha -anomeric form Choose the correct answer from the options given below:

The specific carbohydrate residue present across backbone units in DNA molecules is beta-2-deoxy-D-ribose. Its spatial parameters satisfy the following conditions: - It is a 5-carbon pentose sugars skeleton structure (A). - It maintains a canonical D configuration pathway sequence (C). - When localized in free, open unlinked molecular solutions, it standardly functions as a reducing carbohydrate assembly agent (D). - It exists predominantly in a furanose cycle form inside DNA, rather than a pyranose ring. Ribose in nucleic acids occurs primarily as a five-membered furanose ring configuration system. Class 12 Chemistry: Biomolecules

The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in alpha -anomeric form Choose the correct answer

The specific carbohydrate residue present across backbone units in DNA molecules is beta-2-deoxy-D-ribose. Its spatial parameters satisfy the following conditions: - It is a 5-carbon pentose sugars skeleton structure (A). - It maintains a canonical D configuration pathway sequence (C). - When localized in free, open unlinked molecular solutions, it standardly functions as a reducing carbohydrate assembly agent (D). - It exists predominantly in a furanose cycle form inside DNA, rather than a pyra

The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D…

Year	2026	2025	2024	Total
Questions	9	19	8	36

Year

2026

2025

2024

Total

Questions

Solution & Explanation

Core Logic

The specific carbohydrate residue present across backbone units in DNA molecules is $β$ $\beta$-2-deoxy-D-ribose. Its spatial parameters satisfy the following conditions:

It is a 5-carbon pentose sugars skeleton structure (A).
It maintains a canonical D configuration pathway sequence (C).
When localized in free, open unlinked molecular solutions, it standardly functions as a reducing carbohydrate assembly agent (D).
It exists predominantly in a furanose cycle form inside DNA, rather than a pyranose ring.
Carbohydrates - Nucleic Acids component diagram for Q36 - JEE Main 2025 Morning

Pattern Recognition

Ribose in nucleic acids occurs primarily as a five-membered furanose ring configuration system.

Chapter Mix

Class 12 Chemistry: Biomolecules

More Biomolecules Previous-Year Questions — Page 7

Q jee_main_2024_27_jan_morning Nucleic Acids

Two nucleotides are joined together by a linkage known as:

A. Phosphodiester linkage
B. Glycosidic linkage
C. Disulphide linkage
D. Peptide linkage

Solution

Related Formula

Nucleotides bond phosphodiester linkage:

Nucleotide₁ - O - P(=O)(O^-) - O - Nucleotide₂

Core Logic

Two nucleotides are joined together by phosphodiester linkage between $5'$ $5'$ and $3'$ $3'$ carbon atoms of the pentose sugar.

Phosphodiester linkage diagram for Q61 - JEE Main 2024 Morning

Pattern Recognition

Proteins $arrow$ $\rightarrow$ Peptide, Carbohydrates $arrow$ $\rightarrow$ Glycosidic, Proteins/Cysteine $arrow$ $\rightarrow$ Disulphide, Nucleic Acids $arrow$ $\rightarrow$ Phosphodiester linkage.

Chapter Mix

Class 12 Chemistry: Biomolecules

Q76 jee_main_2024_29_jan_morning Proteins and Amino Acids

Type of amino acids obtained by hydrolysis of proteins is :

A. $β$ $\beta$
B. $α$ $\alpha$
C. $δ$ $\delta$
D. $γ$ $\gamma$

Solution

Core Logic

Proteins are natural biopolymers. The fundamental building blocks (monomers) of all naturally occurring proteins are $α$ $\alpha$-amino acids. In these molecules, both the amino group ( $-NH₂$ $-NH_2$) and the carboxyl group ( $-COOH$ $-COOH$) are attached to the exact same carbon atom, designated as the $α$ $\alpha$-carbon.

Because they are polymers of $α$ $\alpha$-amino acids linked by peptide bonds, the hydrolysis of proteins (acidic, basic, or enzymatic) will cleave these peptide bonds to yield the constituent $α$ $\alpha$-amino acids.

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Class 12 Chemistry: Biomolecules

Q84 jee_main_2024_30_january_evening Nucleic Acids (DNA and RNA)

The total number of correct statements, regarding the nucleic acids is A. RNA is regarded as the reserve of genetic information. B. DNA molecule self-duplicates during cell division C. DNA synthesizes proteins in the cell. D. The message for the synthesis of particular proteins is present in DNA E. Identical DNA strands are transferred to daughter cells.

Numerical Answer. Answer: 3 to 3

Solution

Core Logic

A. RNA is regarded as the reserve of genetic information. (False - DNA is the reserve of genetic information). B. DNA molecule self-duplicates during cell division. (True - through replication). C. DNA synthesizes proteins in the cell. (False - RNA molecules synthesize proteins via translation, DNA only provides the code). D. The message for the synthesis of particular proteins is present in DNA. (True - the genetic code lies in the base sequence of DNA). E. Identical DNA strands are transferred to daughter cells. (True - through accurate replication and cell division, genetic continuity is maintained).

Step 1: Final Conclusion

The true statements are B, D, and E. Total number of correct statements is 3.

Chapter Mix

Class 12 Chemistry: Biomolecules

Q63 jee_main_2024_30_jan_morning Carbohydrates

Sugar which does not give reddish brown precipitate with Fehling's reagent is:

A. $Sucrose$ $\text{Sucrose}$
B. $Lactose$ $\text{Lactose}$
C. $Glucose$ $\text{Glucose}$
D. $Maltose$ $\text{Maltose}$

Solution

Core Logic

Fehling's reagent is reduced by reducing sugars to give a reddish-brown precipitate of $Cu₂O$ $Cu_2O$. Reducing sugars must have a free aldehyde/ketone group or a hemiacetal linkage that can open to form an aldehyde. Sucrose is a non-reducing sugar because its anomeric carbons (C1 of glucose and C2 of fructose) are tied up in a glycosidic linkage, leaving no free hemiacetal group.

Step 1: Analyzing the options

Lactose, glucose, and maltose are all reducing sugars and will give a positive Fehling's test. Sucrose does not.

Pattern Recognition

Sucrose = non-reducing sugar. Maltose, Lactose = reducing sugars. Monosaccharides (glucose, fructose) = always reducing.

Chapter Mix

Class 12 Chemistry: Biomolecules

Q89 jee_main_2024_31_jan_evening Vitamins and their Classification

From the vitamins A,

B₁

B₆

B₁₂

, C, D, E and K, the number vitamins that can be stored in our body is ________

Numerical Answer. Answer: 5 to 5

Solution

Core Logic

Vitamins are broadly classified into two groups based on solubility:

Fat-soluble vitamins: Vitamins A, D, E, and K. These are stored in the liver and adipose (fat-storing) tissues.
Water-soluble vitamins: B group vitamins and Vitamin C. These are readily excreted in urine and cannot be stored in the body (with the exception of Vitamin $B₁₂$ $B_{12}$, which can be stored in the liver).

Step 1: Final List

The vitamins that can be stored in the body from the given list are A, D, E, K, and $B₁₂$ $B_{12}$. Total number = $5$ $5$.

Chapter Mix

Class 12 Chemistry: Biomolecules

The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in $α$ $\alpha$ -anomeric form Choose the correct answer from the options given below:

Solution & Explanation

Core Logic

Pattern Recognition

Chapter Mix

Reference Study Guides

More Biomolecules Previous-Year Questions — Page 7

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Related Formula

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The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in α$\alpha$ -anomeric form Choose the correct answer from the options given below:

Solution & Explanation

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More Biomolecules Previous-Year Questions — Page 7

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The carbohydrates "Ribose" present in DNA, is A. A pentose sugar B. present in pyranose from C. in "D" configuration D. a reducing sugar, when free E. in $α$ $\alpha$ -anomeric form Choose the correct answer from the options given below: