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JEE Main · 2025 · 23 Jan 2025 · Shift 2 · Biomolecules

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The -Helix and -Pleated sheet structures of protein are associated with its:
  1. (A)quaternary structure
  2. (B)primary structure
  3. (C)secondary structure✓ Correct
  4. (D)tertiary structure

Answer: (C)

Solution

The primary structure of a protein is simply its amino-acid sequence, linked by peptide bonds. Secondary structure describes local, regular folding patterns held together by hydrogen bonds between backbone and groups — the two classic examples being the right-handed -helix and the extended -pleated sheet. Tertiary structure is the overall three-dimensional fold of a single chain, stabilised by disulfide bridges and hydrophobic and ionic interactions, while quaternary structure describes the assembly of multiple subunits into one functional protein. The -helix and -pleated sheet are features of secondary structure.

JEE Main · 2025 · 23 Jan 2025 · Shift 2 · Single correct option

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