Folding

February 08/21

We finished up our review of much of the material we have covered thus far. We circled back to intermolecular forces, including introducing the new concept of Coulombic forces. We reviewed organic chemistry and then applied this to the reaction of dihydrofolate to tetrahydrofolate by the enzyme dihydrofolate reductase. We finished by reviewing expression and protein structure.

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February 15/21

In today’s lesson, the students explored what happens after protein expression - protein folding. Here we discussed the basics of thermochemistry, and how entropic gains of water drive protein folding (through the hydrophobic effect). In order to reinforce the concepts learned on protein expression and folding, the students took part in an engaging hands-on activity. First, the students drew the cell and labeled important organelles involved in gene expression. Using pipe cleaners, the students walked through the location of DNA and genes in the nucleus, RNA polymerase transcribing the gene to mRNA, export of mRNA to the cytosol and eventually ribosome, and then translation to form the polypeptide chain. Using pipe cleaners and toothpicks to represent hydrogen bonds, the students then began folding their proteins, starting with various secondary structure elements. Next lesson we will continue folding our proteins, including tertiary and quaternary structure, glycosylation and discuss what happens when folding goes wrong.