Food Analysis Previous Exam IV

University of Kentucky, Department of Animal & Food Sciences, FSC 535


1. True (T) or False (F) (20 pts.)

The charge on a ion produced by most mass spectrometers is positive 1.

The parent ion is the largest fragment produced by the mass spectrometer.

An epitope is the specific binding site on an antibody.

Monoclonal antibodies will bind to only one epitope.

Near-infrared spectroscopy can be used to analyze intact foods.

Near-infrared spectras result primarily from functional groups with a hydrogen attached.

Atomic absorption spectroscopy measures the emission of radiation from an excited atom.

Nuclear magnetic resonance spectras commonly result from hydrogen nuclei.

Differential scanning calorimetry measures the temperature difference between two samples.

Enthalpy is the heat content of a sample.

2. Describe how gel electrophoresis can be combined with an immunoassay. (6 pts.)

3. What is a phase transition and why is it detected by Differential Scanning Calorimetry? (6 pts.)

4. Describe the properties of a conformational antigenic determinant. (5 pts.)

5. Describe two different situation where nuclear magnetic resonance spectroscopy would be a useful method to analyze a food products. What type of information would you obtain from each of these analyses? (8 pts.)

 6. What is the NMR resonance condition and why does it vary between different different regions of a molecule? (6 pts.)

7. Describe the different components of an atomic absorption spectrometer and their functions.(9 pts.)

8. Describe two different situation where differential scanning calorimetry would be a useful method to analyze a food products. What type of information would you obtain from each of these analyses? (8 pts.)

 9. Describe two advantages o GC/MS system has over a GC/flame ionization detector.(5 pts.)

10. List and describe the three major functions of a mass spectrometer? (12 pts.)

11. What is the difference between a total ion chromatogram produced by a mass spectrometer and individual ion traces (or combination of several ion traces)? What is one application for each of these types of chromatograms? (8 pts.)

12. Briefly write down the differences between the following items. (12 pts.)

a. Detection of a linear epitope in a native protein vs. in a denatured protein

b. Polyclonal vs. Monoclonal antibody

c. Standardization of DSC vs. Standardization of NMR

d. Atomic Absorption Spectroscopy vs. Atomic Emission Spectroscopy

e. Mass spectroscopy base peak vs. Parent ion peak

f. Spectral vs Diffuse reflectance Near-Infrared Spectroscopy

13. You have purified a single protein from kangaroo meat that is unique to Kangaroos. You would like to develop a method to assay for adulteration of hamburger meat with kangaroo meat and you want to be sure that the method will work with both raw and cooked meat . Describe any special steps necessary in the preparation, purification, or analysis of this antibody and the design of the assay for kangaroo meat in hamburger..(15 pts.)