Question

Match List-I with List-II 

Choose the correct answer from the options given below: 
 

• 1. (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• 2. (A) - (I), (B) - (III), (C) - (II), (D) - (IV)
• 3. (A) - (I), (B) - (II), (C) - (IV), (D) - (III)
• 4. (A) - (III), (B) - (IV), (C) - (I), (D) - (II)

Hint:

Associate each spectroscopic technique with a key parameter: UV-Vis \(\rightarrow\) Concentration (Beer's Law); Fluorescence \(\rightarrow\) Environment/Conformation; IR \(\rightarrow\) Bond Vibrations/Functional Groups; ESR/EPR \(\rightarrow\) Unpaired Electrons/Dynamics.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
This question requires matching different spectroscopic techniques with their common applications in the field of biophysics. Each technique probes different properties of molecules.
Step 2: Detailed Explanation:
(A) UV-Visible Spectroscopy: This technique measures the absorbance of light by a sample. According to the Beer-Lambert Law (\(A = \epsilon cl\)), absorbance is directly proportional to concentration. It is widely used to determine the concentration of a sample, especially for proteins (at 280 nm) and nucleic acids (at 260 nm). So, (A) matches with (I).
(B) Fluorescence Spectroscopy: This method is highly sensitive to the environment of a fluorescent molecule (fluorophore). Changes in protein folding, ligand binding, or other interactions can alter the fluorescence signal, making it an excellent tool for studying molecular conformation and dynamics. So, (B) matches with (III).
(C) Infrared (IR) Spectroscopy: IR spectroscopy detects the vibrations of chemical bonds within a molecule. The frequencies of these vibrations are characteristic of the types of bonds and their environment. In biophysics, it is used to determine the secondary structure of proteins (e.g., amide I and amide II bands) and identify functional groups, thus revealing chemical characteristics. So, (C) matches with (II).
(D) Electron Spin Resonance (ESR): Also known as Electron Paramagnetic Resonance (EPR), this technique is specific to molecules with unpaired electrons (paramagnetic species). By attaching "spin labels" to molecules of interest, ESR can provide information on their mobility and environment. It is extensively used to study the fluidity of membranes and the dynamics of proteins. So, (D) matches with (IV).
Step 3: Final Answer:
The correct matching is: (A)-(I), (B)-(III), (C)-(II), (D)-(IV). This corresponds to option 2.