Question

An unknown solution shows distinct peaks at 260 and 280 nm in a UV spectrophotometric analysis. The solution may contain

• A. Only proteins.
• B. Proteins, DNA and RNA.
• C. DNA and RNA.
• D. DNA only.

Hint:

260 = Nucleic Acids; 280 = Proteins. A 260/280 ratio helps determine purity.

Answer 1

The Correct Option is B

Step 1: Concept
Ultraviolet (UV) spectroscopy is used to quantify and detect biomolecules based on their specific absorption maxima.

Step 2: Meaning
Nucleic acids (DNA and RNA) have an absorption peak at 260 nm due to the presence of nitrogenous bases, while proteins peak at 280 nm primarily due to aromatic amino acids like Tryptophan and Tyrosine.

Step 3: Analysis
If a solution shows distinct peaks at both 260 nm and 280 nm, it indicates the presence of both nucleic acids and proteinaceous material.

Step 4: Conclusion
Therefore, the solution likely contains a mixture of proteins, DNA, and RNA. Final Answer: (B)