Match List I with List II
| List I | List II |
| A. Glycosidic linkage | I. Monomeric units of nucleic acids |
| B. Peptide linkage | II. Sugar-heterocyclic base combination |
| C. Nucleotide | III. Linkage between two amino acids |
| D. Nucleoside | IV. Linkage between two monosaccharide units |
Choose the correct answers from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-IV, B-III, C-I, D-II
Biomolecules are built from small units joined by particular links: monosaccharides by glycosidic links, amino acids by peptide links, and nucleotides (base + sugar + phosphate) into nucleic acids.
A. Glycosidic linkage — This matches IV. Linkage between two monosaccharide units. Two monosaccharides are joined through an oxygen atom with loss of a water molecule (as in sucrose, maltose, starch).
B. Peptide linkage — This matches III. Linkage between two amino acids. It is the amide bond –CO–NH– formed between the –COOH of one amino acid and the –\( \ce{NH2} \) of another.
C. Nucleotide — This matches I. Monomeric units of nucleic acids. A nucleotide is base + sugar + phosphate; nucleic acids are chains of nucleotides.
D. Nucleoside — This matches II. Sugar-heterocyclic base combination. A base attached at C1′ of the pentose sugar, without phosphate, is a nucleoside.