### Related Formula
Glycosidic linkages define the connectivity between monosaccharide units in disaccharides and polysaccharides.
### Core Logic
Analyzing each saccharide configuration:
- **Sucrose**: Formed by alpha$\alpha$-D-glucose and beta$\beta$-D-fructose via a alpha 1 - beta 2$\alpha 1 - \beta 2$ glycosidic linkage.
- **Maltose**: Composed of two alpha$\alpha$-D-glucose units connected by a alpha 1-4$\alpha 1-4$ glycosidic linkage.
- **Lactose**: Composed of beta$\beta$-D-galactose and beta$\beta$-D-glucose via a beta 1-4$\beta 1-4$ glycosidic linkage.
- **Amylopectin**: A branched polymer of glucose with linear alpha 1-4$\alpha 1-4$ linkages and branching at alpha 1-6$\alpha 1-6$ positions.
### Step 1: Final Mapping
Matching pairs lead to:
(A)-(III), (B)-(I), (C)-(IV), (D)-(II).
### Pattern Recognition
Remember shortcuts for common linkages:
- Sucrose is a non-reducing sugar involving the anomeric carbons of both units (alpha 1 - beta 2$\alpha 1 - \beta 2$).
- Lactose has a beta$\beta$-linkage (beta 1-4$\beta 1-4$).
- Amylopectin represents branched starch (alpha 1-4$\alpha 1-4$ and alpha 1-6$\alpha 1-6$).
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
Keywords:#Match List-I with List-II Saccharides#JEE Main 2025 Evening Q28#Biomolecules JEE Main 2025#Glycosidic-linkages found JEE Main 2025
More Biomolecules Previous-Year Questions
Q67jee_main_2026_21_jan_morningAmino Acids
Identify the correct statements.
A. Arginine and Tryptophan are essential amino acids.
B. Histidine does not contain heterocyclic ring in its structure.
C. Proline is a six membered cyclic ring amino acid.
D. Glycine does not have chiral centre.
E. Cysteine has characteristic feature of side chain as mathrmMeS-CH_2-CH_2-$\mathrm{MeS-CH_2-CH_2-}$.
Choose the correct answer from the options given below:
A.textC and E Only$\text{C and E Only}$
B.textB and E Only$\text{B and E Only}$
C.textC and D Only$\text{C and D Only}$
D.textA and D Only$\text{A and D Only}$
Solution
### Core Logic
A. Arginine and Tryptophan are indeed essential amino acids (cannot be synthesized by the human body). (Correct)
B. Histidine contains an imidazole ring, which is a heterocyclic ring. So statement B is incorrect.
C. Proline contains a pyrrolidine ring, which is a five-membered cyclic ring. So statement C is incorrect.
D. Glycine is mathrmNH_2-CH_2-COOH$\mathrm{NH_2-CH_2-COOH}$. Because its alpha carbon has two identical hydrogen atoms attached, it lacks a chiral center. (Correct)
E. Cysteine's side chain is a thiol group (-mathrmCH_2-SH$-\mathrm{CH_2-SH}$), not a thioether (mathrmMeS-CH_2-CH_2-$\mathrm{MeS-CH_2-CH_2-}$ which belongs to Methionine). So statement E is incorrect.
Correct statements: A and D.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
Q44jee_main_2025_02_april_eveningProteins and Amino Acid Sequences
A tetrapeptide "x" on complete hydrolysis produced glycine (Gly), alanine (Ala), valine (Val), leucine (Leu) in equimolar proportion each. The number of tetrapeptides (sequences) possible involving each of these amino acids is
A. 16
B. 32
C. 8
D. 24
Solution
### Related Formula
textNumber of unique sequences = n!$$\text{Number of unique sequences} = n!$$
### Core Logic
A **tetrapeptide** is formed by connecting four amino acids through three peptide linkages.
Since the problem specifies that complete hydrolysis of the tetrapeptide produces Gly, Ala, Val, and Leu in *equimolar proportions*, the peptide must contain exactly one molecule of each of these four distinct amino acids.
### Step 1: Calculate the Permutations
The number of unique peptide sequences corresponds to the number of ways we can arrange these 4 distinct amino acids:
textNumber of permutations = 4! = 4 times 3 times 2 times 1 = 24$$\text{Number of permutations} = 4! = 4 \times 3 \times 2 \times 1 = 24$$
### Pattern Recognition
Combinatorics in Chemistry: If we have n$n$ unique, non-repeating amino acids, the number of linear isomeric peptides is n!$n!$. If repetition were permitted, the number of possible peptides would be n^n$n^n$ (which would be 4^4 = 256$4^4 = 256$ in this case).
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
Qjee_main_2025_02_april_morningMolar Mass Calculations
0.1mathrm~mol$0.1\mathrm{~mol}$ of the following given antiviral compound (P) will weigh times 10^-1mathrm~g$\times 10^{-1}\mathrm{~g}$The diagram displays the full multi-cyclic skeletal structure of an antiviral nucleoside molecule featuring explicit iodine and fluorine atomic positions.
(Given : molar mass in mathrmg cdot mol^-1$\mathrm{g \cdot mol}^{-1}$ H: 1, C: 12, N: 14, O: 16, F: 19, I: 127)
Numerical Answer.Answer: 372 to 372
Solution
### Related Formula
Standard molecular weight calculation formula system:
textMolar Mass = sum (textAtom Count times textAtomic Weight)$$\text{Molar Mass} = \sum (\text{Atom Count} \times \text{Atomic Weight})$$textMass = textMoles times textMolar Mass$$\text{Mass} = \text{Moles} \times \text{Molar Mass}$$
### Core Logic
Let's tabulate and sum up the constituent atoms based on the verified structural formula layout :
* Counting positions meticulously yields a molecular identity formula of mathrmC_9H_10FIN_2O_4$\mathrm{C_9H_{10}FIN_2O_4}$.
* Calculating the total molar mass:
textMass = (9 times 12) + (10 times 1) + 19 + 127 + (2 times 14) + (4 times 16)$$\text{Mass} = (9 \times 12) + (10 \times 1) + 19 + 127 + (2 \times 14) + (4 \times 16)$$textMass = 108 + 10 + 19 + 127 + 28 + 64 = 372mathrm~g/mol$$\text{Mass} = 108 + 10 + 19 + 127 + 28 + 64 = 372\mathrm{~g/mol}$$The diagram displays the full multi-cyclic skeletal structure of an antiviral nucleoside molecule featuring explicit iodine and fluorine atomic positions.
### Step 1: Final Mass Scaling
Find the mass of 0.1mathrm~mol$0.1\mathrm{~mol}$ of the sample:
textWeight = 0.1 times 372 = 37.2mathrm~g = 372 times 10^-1mathrm~g$$\text{Weight} = 0.1 \times 372 = 37.2\mathrm{~g} = 372 \times 10^{-1}\mathrm{~g}$$
Hence, the integer value for the blank box is 372.
### Pattern Recognition
When counting atoms in nucleoside structures, remember that each vertex in the ribose sugar ring represents a fully saturated carbon component unless double bonds or heteroatoms are explicitly drawn.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
Class 11 Chemistry: Some Basic Concepts of Chemistry
B.(2)\ textAll naturally occurring amino acids are optically active.$(2)\ \text{All naturally occurring amino acids are optically active.}$
C.(3)\ textGlutamic acid is the only amino acid that contains a -COOH group at the side chain.$(3)\ \text{Glutamic acid is the only amino acid that contains a -COOH group at the side chain.}$
D.(4)\ textAmino acid, cysteine easily undergo dimerization due to the presence of free SH group.$(4)\ \text{Amino acid, cysteine easily undergo dimerization due to the presence of free SH group.}$
Solution
### Related Formula
Dimerization of thiol pairs yields a disulfide linkage via an oxidation mechanism:
mathrm2R-SH xrightarrow[-H_2] R-S-S-R$$\mathrm{2R-SH \xrightarrow{[-H_2]} R-S-S-R}$$
### Core Logic
Let's review each choice item factually layout-by-row:
* Option 1 is inaccurate: Isoleucine and threonine contain two distinct chiral centers.
* Option 2 is inaccurate: Glycine lacks a asymmetric center, rendering it optically inactive.
* Option 3 is inaccurate: Aspartic acid similarly contains a carboxylic acid functional group along its side chain.
* Option 4 is correct: Cysteine contains a highly active free functional -mathrmSH$-\mathrm{SH}$ group that easily dimerizes to form Cystine through a disulfide loop matrix.
### Pattern Recognition
Disulfide bridges formed by cysteine play a crucial role in maintaining the tertiary and quaternary structural configurations of complex protein folds.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
Fat soluble vitamins are:
A. Vitamin mathrmB_1$\mathrm{B}_1$
B. Vitamin mathrmC$\mathrm{C}$
C. Vitamin mathrmE$\mathrm{E}$
D. Vitamin mathrmB_12$\mathrm{B}_{12}$
E. Vitamin mathrmK$\mathrm{K}$
Choose the correct answer from the options given below :
A. C & D Only
B. A & B Only
C. B & C Only
D. C & E Only
Solution
### Related Formula
Vitamins are classified into two categories based on solubility:
- Water-soluble: Vitamin B-complex and Vitamin C.
- Fat-soluble: Vitamins A, D, E, and K.
### Core Logic
Categorize each given vitamin:
- Vitamin mathrmB_1$\mathrm{B}_1$ (Thiamine) rightarrow$\rightarrow$ Water-soluble
- Vitamin mathrmC$\mathrm{C}$ (Ascorbic acid) rightarrow$\rightarrow$ Water-soluble
- Vitamin mathrmE$\mathrm{E}$ (Tocopherol) rightarrow$\rightarrow$ Fat-soluble
- Vitamin mathrmB_12$\mathrm{B}_{12}$ (Cobalamin) rightarrow$\rightarrow$ Water-soluble
- Vitamin mathrmK$\mathrm{K}$ (Phylloquinone) rightarrow$\rightarrow$ Fat-soluble
### Step 1: Select correct options
Only C (Vitamin mathrmE$\mathrm{E}$) and E (Vitamin mathrmK$\mathrm{K}$) are fat-soluble. Thus, the correct option is (4).
### Pattern Recognition
Use the mnemonic 'ADEK' to remember the fat-soluble vitamins. All other vitamins (mainly B-complex and C) are water-soluble.
### Evaluation Rubric / Model Answer
null
### Chapter Mix
Class 12 Chemistry: Biomolecules
More Biomolecules Questions — jee_main_2025_28_jan_evening
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