Molecular Modeling in Food Science

1. This work was supported by GK-12 NSF award # 0841377 Scientists as Teachers, Teachers as Scientists Matthew Sender (Temple University), Gaetano Amoroso (W.B. Saul High School of Agricultural Sciences) Background Polarity by Color Mixing Non-Polar Molecules (Fats) With Polar Molecules (Water) Amino Acids and Proteins THE CHALLENGE: To help high school students see their food through the lens of chemistry. THE APPROACH: To use physical/computer models of molecules to visualize food as molecules. W.B. Saul High School is located on a bucolic campus in Philadelphia, Pa. It boasts one of the nation’s largest Future Farmers of America chapters. Gaetano Amoroso has taught food and meat science for the past 20 years. Prior to teaching Mr. Amoroso worked for 22 years in food service and preparation businesses. Matthew Sender is a PhD candidate in organic chemistry at Temple University. He synthesiszes and studies isostericproline analogs with Dr. Grant Krow. The food and meat science classes consist of a mix of juniors and seniors. Most have little to no exposure to chemistry. End View Bile Salts: Cholic Acid is a bile salt that works to both neutralize stomach acid and emulsify fats. A flat molecule, cholic acid has two faces. Side View End View Side View The most abundant elements in food are: Molecular Modeling in Food Science Carbon Hydrogen Oxygen Nitrogen Sulfur Phosphorous Hydrophobic Face (water fearing) Non-polar Polar Hydrophilic Face (water loving) PDB code: 2JQY PDB code: 2BG9 H2O = Water = Both of these proteins are made from the same set of molecules: 20 Amino Acids. How is this possible? Students learn to use the model sets by building simple molecules that they have real life experience with. Students discover what makes an amino acid an amino acid by building several and discussing the similarities and differences. In understanding what an amino acid is, students are able to grasp what makes proteins different from fats and carbohydrates. Conclusions Utilizing the opposite nature of the two faces, cholic acid can assemble around fat (or other non-polar) molecules forming an emulsion. Red goes with red, grey goes with grey. Water is a polar molecule C57H110O6 = Sterin (fat) = Coding chemical behavior by colors allows for conceptual understanding without prior knowledge of the underlying chemical principals. Using this idea, we have compared fats, sugars, and proteins. By contrasting the differences in elemental composition and 3D structure, students were exposed to the foundational differences in food molecules. In building the different molecules with their own hands they discover the structural implications of bonding patterns such as chirality and geometric isomerism. For many of the students, building models was the Aha moment of comprehending a chemical formula. Sterin is a non-polar molecule Sterin (fat) and water are not miscible (do not mix). How do we deal with fats in our digestive system? This lesson applies the concept of polarity to a known entity (oil and water do not mix). It can also be extended to concepts such as soaps and how soaps and fats are related, and also the lipid bilayer in cells. Soap Fat bile salts Amino Acids Proteins