Question

Site directed mutagenesis facilitated research on

• A. Carbohydrates
• B. Proteins
• C. Lipids
• D. Fats

Hint:

Site-directed mutagenesis is a powerful technique for studying protein function by introducing specific mutations in the DNA sequence encoding the protein.

Answer 1

The Correct Option is B

Carbohydrates, lipids, and fats are all built and modified by metabolic enzymes rather than being directly specified codon-by-codon by a gene sequence, so changing a gene's DNA sequence does not translate into a precise, targeted change in these molecules.

Proteins are different: each codon in a gene directly specifies one amino acid, so site-directed mutagenesis lets researchers change a single amino acid and observe exactly how that change affects the protein's structure or function.

This direct gene-to-molecule correspondence is why site-directed mutagenesis has been used mainly to study proteins.

Answer 2

Considering how this technique has actually been applied in research history reinforces the answer.

1. Carbohydrates: Structural studies of carbohydrates typically rely on techniques like NMR or crystallography paired with enzymatic synthesis, not gene-level mutagenesis.
2. Proteins: Site-directed mutagenesis has been the workhorse technique behind decades of enzyme mechanism and structure-function studies, precisely because altering one codon lets a researcher swap out one specific amino acid and test its role.
3. Lipids: Lipid research generally proceeds through biochemical extraction, enzymatic pathway studies, and mass spectrometry rather than through single-codon gene edits.
4. Fats: As with lipids generally, fat composition and metabolism are studied through pathway and enzyme-level approaches, not by mutating the DNA sequence of a gene encoding the fat itself, since fats have no such encoding gene.

The decades of research application confirm that this technique's natural target is protein structure-function studies.

So, the correct answer is proteins.