Question

All the following can determine the protein structure except

• A. Mass spectrometry
• B. X-ray crystallography
• C. High performance liquid chromatography
• D. NMR spectroscopy

Answer 1

The Correct Option is C

To determine the three-dimensional (3D) structure of proteins, specialized analytical techniques are employed. Let's review each option and see why or why not it is suitable for determining protein structures:

1. Mass spectrometry: Mass spectrometry is primarily used for determining the mass, identify the protein, and analyzing the quantity of proteins. It is not typically used to directly determine the 3D structure of proteins.
2. X-ray crystallography: This is a widely used method to determine the 3D atomic structure of proteins. By measuring the patterns of X-rays diffracted by a crystallized sample of the protein, scientists can construct a detailed map of electron densities within the protein, thus deducing its structure.
3. High performance liquid chromatography (HPLC): HPLC is mainly used for separating, identifying, and quantifying components in a mixture. It is not used for determining the 3D structure of proteins. Therefore, this is the correct answer, as it cannot determine protein structure.
4. NMR spectroscopy: Nuclear Magnetic Resonance (NMR) spectroscopy can be used to determine the structure of proteins in solution by measuring the magnetic properties of atomic nuclei. It provides information on the 3D arrangement of atoms in the protein.

The correct answer is therefore High performance liquid chromatography, as this technique is not involved in determining the 3D structure of proteins but rather in separating and identifying components of mixtures.